tag:blogger.com,1999:blog-71915412011-04-21T17:44:03.453-07:00LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.comBlogger551100tag:blogger.com,1999:blog-7191541.post-1102025959432943342004-12-02T14:19:00.000-08:002004-12-02T14:19:19.433-08:00Chapter 29, part 2 <br />Development and Inheritance <br />SECTION 29-5 The Second and Third Trimesters <br />Second and Third Trimesters <br />Second trimester <br />Organ systems increase in complexity <br />Third trimester <br />Many organ systems become fully functional <br />Fetus undergoes largest weight change <br />At end of gestation fetus and uterus push maternal organs out of position <br />Figure 29.9 The Second and Third Trimesters <br />Figure 29.10 Growth of the Uterus and Fetus <br />Figure 29.10 Growth of the Uterus and Fetus <br />Developing fetus totally dependent on maternal organs <br />Maternal adaptations include increased <br />Respiratory rate <br />Tidal volume <br />Blood volume <br />Nutrient and vitamin uptake <br />Glomerular filtration rate <br />Structural and Functional Changes in the Uterus <br />Progesterone inhibits uterine muscle contraction <br />Opposed by estrogens, oxytocin and prostaglandins <br />Multiple factors interact to produce labor contractions in uterine wall <br />Figure 29.11 Factors Involved in the Initiation of Labor and Delivery <br />SECTION 29-6 Labor and Delivery <br />Goal of labor is parturition <br />Stages of labor <br />Dilation <br />The cervix dilates and fetus moves toward cervical canal <br />Expulsion <br />The cervix completes dilation and fetus emerges <br />Placental <br />Ejection of the placenta <br />Figure 29.12 The Stages of Labor <br />Other labor and delivery situations <br />Premature labor <br />True labor begins before fetus has completed normal development <br />Difficult deliveries <br />When the fetus faces the pubis rather than the sacrum <br />The legs or buttocks enter the vaginal canal first (breech births) <br />Multiple births <br />Twins, triplets, etc. <br />Dizygotic or monozygotic situations <br />SECTION 29-7 Postnatal Development <br />Postnatal life stages <br />Neonatal period <br />Infancy <br />Childhood <br />Adolescence <br />Maturity <br />Senescence begins at maturity and ends in death <br />The neonatal period <br />From birth to one month <br />Respiratory, circulatory, digestive and urinary systems adjust <br />Infant must thermoregulate <br />Maternal mammary glands secrete colostrum first few days <br />Milk production thereafter <br />Both secretions are released via the milk let-down reflex <br />Body proportions change during infancy and childhood <br />Figure 29.13 The Milk Let-Down Reflex <br />Figure 29.14 Growth and Changes in Body Form <br />Adolescence <br />Begins at puberty <br />The period of sexual maturation <br />Ends when growth is completed <br />Puberty marked by <br />Increased production of GnRH <br />Rapid increase in circulating FSH and LH <br />Ovaries and testes become sensitive to FSH / LH <br />Gamete production initiated <br />Sex hormones produced <br />Growth rate increases <br />Hormonal changes at puberty produce gender specific differences in system <br />Differences are retained throughout life <br />Adolescence continues until growth completed <br />Further changes occur when sex hormones decline <br />Menopause <br />Male climacteric <br />Senescence <br />Aging affects functional capabilities of all system <br />SECTION 29-8 Genetics, Development, and Inheritance <br />Genes and chromosomes <br />Every somatic cell carries copies of the 46 original chromosomes in the zygote <br />Genotype – Chromosomes and their component genes <br />Phenotype – physical expression of the genotype <br />Patterns of inheritance <br />Somatic cells contain 23 pairs of chromosomes <br />Homologous chromosomes <br />22 pair of autosomes and one pair of sex chromosomes <br />Chromosomes contain DNA <br />Genes are functional segments of DNA <br />Figure 29.15 Human Chromosomes <br />Various forms of a gene are called alleles <br />Homozygous if homologous chromosomes carry the same alleles <br />Heterozygous if homologous chromosomes carry different alleles <br />Alleles are either dominant or recessive depending on expression <br />Punnett square diagram predicts characteristics of offspring <br />Figure 29.16 Predicting Phenotypic Characteristics by Using Punnett Squares <br />Inheritance <br />Simple inheritance <br />Phenotypic characteristics are determined by interactions between single pair of alleles <br />Polygenic inheritance <br />Phenotypic characteristics are determined by interactions among alleles on several genes <br />Sources of individual variation <br />Genetic recombination <br />Gene reshuffling <br />Crossing over and translocation <br />Occurs during meiosis <br />Spontaneous mutations <br />Random errors in DNA replication <br />Figure 29.17 Crossing over and Translocation <br />Sex-linked inheritance <br />Sex chromosomes are X chromosome and Y chromosome <br />Male = XY <br />Female = XX <br />X chromosome carries X-linked (sex linked) genes <br />Affect somatic structures <br />Have no corresponding alleles on Y chromosome <br />Figure 29.18 X-Linked inheritance <br />The Human Genome Project <br />Mapped more than 38,000 of our genes <br />Including some responsible for inherited disorders <br />Figure 29.19 A Map of the Human Chromosomes <br />You should now be familiar with: <br />The relationship between differentiation and development, and the various stages of development <br />The process of fertilization <br />The three prenatal periods and describe the major events associated with each <br />The importance of the placenta as an endocrine organ <br />You should now be familiar with: <br />The structural and functional changes in the uterus during gestation <br />The events that occur during labor and delivery <br />The basic principles of genetics as they relate to the inheritance of human traits <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110202595943294334?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com4tag:blogger.com,1999:blog-7191541.post-1102025765830814052004-12-02T14:15:00.000-08:002004-12-02T14:16:05.830-08:00Chapter 29, part 1 <br />Development and Inheritance <br />Learning Objectives <br />Explain the relationship between differentiation and development and specify the various stages of development <br />Describe the process of fertilization <br />List the three prenatal periods and describe the major events associated with each <br />Discuss the importance of the placenta as an endocrine organ <br />Learning Objectives <br />Discuss the structural and functional changes in the uterus during gestation <br />List and discuss the events that occur during labor and delivery <br />Relate basic principles of genetics to the inheritance of human traits <br />SECTION 29-1 An Overview of Topics in Development <br />Differentiation and development <br />Development <br />Gradual modification of physical and physiological characteristics <br />Differentiation <br />The creation of different types of cells <br />Stages of development <br />Prenatal development <br />Embryological <br />Changes occurring the first two months after fertilization <br />Fetal <br />Begins at the start of the ninth week and continues until birth <br />Postnatal development <br />Commences at birth and continues to maturity <br />SECTION 29-2 Fertilization <br />Fertilization (conception) <br />Occurs in the uterine tubes <br />Within a day of ovulation <br />Spermatozoa cannot fertilize an ovum until after capacitation <br />Figure 29.1 Fertilization <br />Figure 29.1 Fertilization <br />The Oocyte at Ovulation <br />Oocyte is in meiosis II <br />Surrounded by the corona radiate <br />Spermatozoa release hyaluronidase and acrosin <br />Enzymes required to penetrate corona radiate <br />Single spermatozoan contacts oocyte, fertilization begins <br />Oocyte activation <br />Oocyte activation <br />Oocyte completes meiosis II <br />Functionally mature ovum <br />Female pronucleus and male pronucleus fuse (amphimixis) <br />Polyspermy prevented by membrane depolarization and cortical reaction <br />SECTION 29-3 The Stages of Prenatal Development <br />Embryonic and Fetal Periods <br />Induction <br />During prenatal development differences in cytoplasmic composition trigger changes in genetic activity <br />Gestation periods <br />Three trimesters <br />SECTION 29-4 The First Trimester <br />The First Trimester <br />Cleavage <br />Zygote becomes a preembryo then a blastocyst <br />Implantation <br />Blastocyst burrows into uterine endometrium <br />Placentation <br />Blood vessels form around blastocyst and placenta develops <br />Embryogenesis <br />Formation of a viable embryo <br />Cleavage and blastocyst formation <br />A series of cell divisions that subdivides the cytoplasm of the zygote <br />Trophoblast – outer layer of cells <br />Inner cell mass – cluster of cells at one end of blastocyst <br />Figure 29.2 Cleavage and Blastocyst Formation <br />Implantation <br />Occurs about 7 days after fertilization <br />Trophoblast enlarges and spreads <br />Maternal blood flows through open lacunae <br />Gastrulation <br />Embryonic disc composed of germ layers <br />Endoderm <br />Mesoderm <br />Ectoderm <br />Figure 29.3 Stages in Implantation <br />Figure 29.4 The Inner Cell Mass and Gastrulation <br />Germ layers <br />Gastrulation <br />By day 12 surface cells move toward the primitive streak <br />A third germ layer forms <br />The three germ layers are: <br />Ectoderm – superficial cells that did not migrate <br />Endoderm – cells facing the blastocoele <br />Mesoderm – migrating cells between ectoderm and endoderm <br />Extraembryonic Membranes <br />Four extraembryonic membranes: <br />Yolk sac <br />Amnion <br />Allantois <br />Chorion <br />Figure 29.5 Extraembryonic Membranes and Placenta Formation <br />Figure 29.5 Extraembryonic Membranes and Placenta Formation <br />Figure 29.5 Extraembryonic Membranes and Placenta Formation <br />Embryo Anatomy <br />Yolk sac <br />Important site of blood cell formation <br />Amnion <br />Encloses fluid that surrounds and cushions developing embryo <br />Allantois <br />Eventually becomes bladder <br />Chorion <br />Figure 29.6 A Three-Dimensional View of Placental Structure <br />Placentation <br />Chorionic villi extend into maternal tissue <br />Forms intricate branching network for maternal blood <br />Umbilical cord connects fetus to placenta <br />Hormones of the placenta <br />Trophoblast secretes hormones to maintain pregnancy <br />HCG <br />Estrogens <br />Progesterone <br />hPL <br />Placental prolactin <br />relaxin <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110202576583081405?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1101249572089634352004-11-23T14:35:00.000-08:002004-11-23T14:39:32.090-08:00Are you aware that there is really only one meeting session to go over all thwe material? <br />I do not believe that we can do that. Especially with the genetic cross problems and developmental models. Really need to have the lab final on the day of the lecture fianl. It really will not make a difference. Material is the same, it would still be like studying once. You just have an extra week to accomplish the task! <br /> <br /> <br />sincerely, <br /> <br />Mr. Lechko <br /> <br /> <br />send e-mail; <a href="mailto:canucmelml@hotmail.com">canucmelml@hotmail.com</a> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110124957208963435?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100817259977837272004-11-18T14:33:00.000-08:002004-11-18T14:34:19.976-08:00Chapter 28, part 4 <br />The Reproductive System <br />Uterine cycle <br />Repeating series of changes in the endometrium <br />Continues from menarche to menopause <br />Menses <br />Degeneration of the endometrium <br />Menstruation <br />Proliferative phase <br />Restoration of the endometrium <br />Secretory phase <br />Endometrial glands enlarge and accelerate their rates of secretion <br />Figure 28.20 The Uterine Cycle <br />The vagina <br />Major functions <br />Passageway for elimination of menstrual fluids <br />Receives the penis during sexual intercourse <br />Forms the inferior portion of the birth canal <br />Figure 28.21 The Histology of the Vagina <br />External genitalia <br />Vulva <br />Vestibule <br />Labia minora and majora <br />Paraurethral glands <br />Clitoris <br />Lesser and greater vestibular glands <br />Figure 28.22 The Female External Genitalia <br />Mammary glands <br />Pectoral fat pad <br />Nipple surrounded by the areola <br />Function in lactation under control of reproductive hormones <br />Figure 28.23 The Mammary Glands <br />Hormones of the female reproductive cycle <br />Control the reproductive cycle <br />Coordinate the ovarian and uterine cycles <br />Hormones of the female reproductive cycle <br />Key hormones include: <br />FSH <br />Stimulates follicular development <br />LH <br />Maintains structure and secretory function of corpus luteum <br />Estrogens <br />Have multiple functions <br />Progesterones <br />Stimulate endometrial growth and secretion <br />Figure 28.25 The Hormonal Regulation of Ovarian Activity <br />Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle <br />Figure 28.26 The Hormonal Regulation of the Female Reproductive Cycle <br />SECTION 28-4 The Physiology of Sexual Intercourse <br />Male sexual function <br />Arousal <br />Leads to erection of the penis <br />Parasympathetic outflow over the pelvic nerves <br />Emission and ejaculation <br />Occur under sympathetic stimulation <br />Results in semen being pushed toward external urethral opening <br />Detumescence <br />Subsidence of erection <br />Mediated by the sympathetic nervous system <br />Female sexual function <br />Stages are comparable to those of male sexual function <br />Arousal causes clitoral erection <br />Vaginal surfaces are moistened <br />Parasympathetic stimulation causes engorgement of blood vessels in the nipples <br />SECTION 28-5 Aging and the Reproductive System <br />Menopause <br />The time that ovulation and menstruation cease <br />Typically around age 45-55 <br />Accompanied by a decline in circulating estrogen and progesterone <br />Rise in GnRH, FSH, LH <br />Male climacteric <br />Levels of circulating testosterone begin to decline <br />FSH and LH levels rise <br />Gradual reduction in sexual activity <br />You should now be familiar with: <br />The components of the reproductive system, and their functions <br />The components of the male and female reproductive systems <br />The processes of meiosis and gametogenesis in both sexes <br />You should now be familiar with: <br />The roles played by the male reproductive tract and accessory glands in the functional maturation, nourishment, storage, and transport of spermatozoa <br />The anatomical, physiological, and hormonal aspects of the male and female reproductive cycles <br />The physiology of sexual intercourse <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081725997783727?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100817134465432932004-11-18T14:31:00.000-08:002004-11-18T14:32:14.466-08:00Chapter 28, part 3 <br />The Reproductive System <br />SECTION 28-3 The Reproductive System of the Female <br />Principle organs of the female reproductive system <br />Ovaries <br />Uterine tubes <br />Uterus <br />Vagina <br />Support and stabilization <br />Ovaries, uterine tubes and uterus enclosed within broad ligament <br />Mesovarium supports and stabilizes ovary <br />Figure 28.13 The Female Reproductive System <br />The ovaries <br />Held in position by ovarian and suspensory ligaments <br />Blood vessels enter at ovarian hilus <br />Tunica albuginea covers ovary <br />Figure 28.14 The Ovaries and Their Relationships to the Uterine Tube and Uterus <br />Oogenesis <br />Ovum production <br />Occurs monthly in ovarian follicles <br />Part of ovarian cycle <br />Follicular phase (preovulatory) <br />Luteal phase (postovulatory) <br />Figure 28.15 Oogenesis <br />The ovarian cycle <br />Steps in the ovarian cycle <br />Formation of primary, secondary, and tertiary follicles <br />Ovulation <br />Formation and degeneration of the corpus luteum <br />Degradation of the corpus luteum <br />Figure 28.16 The Ovarian Cycle <br />Figure 28.16 The Ovarian Cycle <br />The Uterine tubes <br />Uterine tubes (Fallopian tubes or oviducts) <br />Infundibulum <br />End closest to the ovary with numerous fimbriae <br />Ampulla <br />The middle portion <br />Isthmus <br />A short segment connected to the uterine wall <br />Each uterine tube opens directly into uterine cavity <br />Fertilization occurs in uterine tube <br />12-24 hours after ovulation <br />During passage from infundibulum to uterus <br />Figure 28.17 The Uterine Tubes <br />The uterus <br />Muscular organ <br />Mechanical protection <br />Nutritional support <br />Waste removal for the developing embryo and fetus <br />Supported by the broad ligament and 3 pairs of suspensory ligaments <br />Uterus <br />Major anatomical landmarks <br />Body <br />Isthmus <br />Cervix <br />Cervical os (internal orifice) <br />Uterine cavity <br />Cervical canal <br />Internal os (internal orifice) <br />Uterine wall consists of three layers: <br />Myometrium – outer muscular layer <br />Endometrium – a thin, inner, glandular mucosa <br />Perimetrium – an incomplete serosa continuous with the peritoneum <br />Figure 28.18 The Uterus <br />Figure 28.18 The Uterus <br />Figure 28.19 The Uterine Wall <br />Figure 28.19 The Uterine Wall <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081713446543293?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100817029568694182004-11-18T14:30:00.000-08:002004-11-18T14:30:29.570-08:00Chapter 28, part 2 <br />The Reproductive System <br />Spermatogenesis <br />Seminiferous tubules <br />Contain spermatogonia <br />Stem cells involved in spermatogenesis <br />Contain sustentacular cells <br />Sustain and promote development of sperm <br />Figure 28.5 The Seminiferous Tubules <br />Figure 28.5 The Seminiferous Tubules <br />Figure 28.6 Chromosomes in Mitosis and Meiosis <br />Spermatogenesis <br />Spermatogenesis involves three processes <br />Mitosis <br />Meiosis <br />Spermiogenesis <br />Figure 28.7 Spermatogenesis <br />Anatomy of spermatozoon <br />Each spermatozoon has: <br />Head <br />Nucleus and densely packed chromosomes <br />Middle piece <br />Mitochondria that produce the ATP needed to move the tail <br />Tail <br />The only flagellum in the human body <br />Figure 28.8 Spermiogenesis and Spermatozoon Structure <br />Male reproductive tract <br />Testes produce mature spermatozoa <br />Sperm enter epididymus <br />Elongated tubule with head, body and tail regions <br />Monitors and adjusts fluid in seminiferous tubules <br />Stores and protects spermatozoa <br />Facilitates functional maturation of spermatozoa <br />Figure 28.9 The Epididymus <br />Ductus deferens AKA vas deferens <br />Begins at epididymus <br />Passes through inguinal canal <br />Enlarges to form ampulla <br />Ejaculatory duct at base of seminal vesicle and ampulla <br />Empties into urethra <br />Urethra <br />Urinary bladder to tip of penis <br />Three regions <br />Prostatic <br />Membranous <br />Penile <br />Accessory glands <br />Seminal vesicles <br />Active secretory gland <br />Contributes ~60% total volume of semen <br />Secretions contain fructose, prostaglandins, fibrinogen <br />Accessory glands <br />Prostate gland <br />Secretes slightly acidic prostate fluid <br />Bulbourethral glands <br />Secrete alkaline mucus with lubricating properties <br />Figure 28.10 The Ductus Deferens and Accessory Glands <br />Contents of Semen <br />Typical ejaculate = 2-5 ml fluid <br />Contains between 20 – 100 million spermatozoa per ml <br />Seminal fluid <br />A distinct ionic and nutritive glandular secretion <br />External genitalia <br />Male external genitalia consist of the scrotum and the penis <br />Skin overlying penis resembles scrotum <br />Penis <br />Contains three masses of erectile tissue <br />2 corpora cavernosa beneath fascia <br />1 corpus spongiosum surrounding urethra <br />Dilation of erectile tissue produces erection <br />Figure 28.11 The Penis <br />Hormones and male reproductive function <br />FSH (Follicle stimulating hormone) <br />Targets sustentacular cells to promote spermatogenesis <br />LH (leutinizing hormone) <br />Causes secretion of testosterone and other androgens <br />GnRH (Gonadotropin releasing hormone) <br />Testosterone <br />Most important androgen <br />Figure 28.12 Hormonal Feedback and the Regulation of the Male Reproductive Function <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081702956869418?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1100816861561035372004-11-18T14:27:00.000-08:002004-11-18T14:27:41.560-08:00Chapter 28, part 1 <br />The Reproductive System <br />SECTION 28-1 The Reproductive System <br />Learning Objectives <br />Specify the components of the reproductive system, and summarize their functions <br />Describe the components of the male and female reproductive systems <br />Outline the processes of meiosis and gametogenesis in both sexes <br />Explain the roles played by the male reproductive tract and accessory glands in the functional maturation, nourishment, storage, and transport of spermatozoa <br />Learning Objectives <br />Summarize the anatomical, physiological, and hormonal aspects of the male and female reproductive cycles <br />Discuss the physiology of sexual intercourse <br />Reproductive System <br />Reproductive system functions in gamete <br />Production <br />Storage <br />Nourishment <br />Transport <br />Fertilization <br />Fusion of male and female gametes to form a zygote <br />SECTION 28-1 Introduction to the Reproductive System <br />Reproductive system includes: <br />Gonads (testes, ovaries) <br />Ducts <br />Accessory glands and organs <br />External genitalia <br />Males and Females <br />Males <br />Testes produce spermatozoa <br />Expelled from body in semen during ejaculation <br />Females <br />Ovaries produce oocytes <br />Immature ovum <br />Travels along uterine tube toward uterus <br />Vagina connects uterus with exterior of body <br />SECTION 28-2 The Reproductive System of the Male <br />Male Reproductive System <br />Pathway of spermatozoa <br />Epididymis <br />Ductus deferens <br />Ejaculatory duct <br />Accessory organs <br />Seminal vesicles <br />Prostate gland <br />Bulbourethral glands <br />Scrotal sac encloses testes <br />Penis <br />Figure 28.1 The Male Reproductive System <br />The testes <br />Descent of the testes <br />Movement of testes through inguinal canal into scrotum <br />Occurs during fetal development <br />Testes remain connected to internal structures <br />Spermatic cords <br />Figure 28.2 The Descent of the Testes <br />Figure 28.2 The Descent of the Testes <br />Figure 28.3 The Male Reproductive System in Anterior View <br />Male Anatomy <br />Musculature of scrotal sac <br />Dartos muscle wrinkles scrotal sac <br />Cremaster muscle pulls sac close to body <br />Testes anatomy <br />Tunica albuginea surrounds testis <br />Septa extend from tunica albuginea to epididymus <br />Lobules <br />Sperm production <br />In seminiferous tubules <br />Interstitial cells between seminiferous tubules <br />Secrete sex hormones <br />Sperm pass through rete testis <br />Efferent ductules connect rete testis to epididymus <br />Figure 28.4 The Structure of the Testes <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-110081686156103537?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692663923988322004-11-05T14:10:00.000-08:002004-11-05T14:11:03.923-08:00SECTION 22-6 B Cells and Antibody-mediated Immunity <br />B cell sensitization of activation <br />Sensitization – the binding of antigens to the B cell membrane antibodies <br />Antigens then displayed on B cell Class II MHC <br />TH cells activated by same antigen stimulate B cell <br />Active B cell differentiates into Memory B Cell or Plasma cell <br />Plasma cells synthesize and release antibody <br />Figure 22.20 The Sensitization and Activation of B Cells <br />Antibodies structure <br />Antibodies are Y-shaped proteins consisting of: <br />Two parallel polypeptide chains <br />Heavy chains and light chains <br />Constant region and variable region <br />Antigen binding site <br />Figure 22.21 Antibody Structure <br />Figure 22.21 Antibody Structure <br />Figure 22.21 Antibody Structure <br />Actions of antibodies include: <br />Neutralization <br />Agglutination and precipitation <br />Activation of complement <br />Attraction of phagocytes <br />Opsinization <br />Stimulation of inflammation <br />Prevention of adhesion <br />Classes of Antibodies (immunoglobins) <br />IgG – resistance against many viruses, bacteria and bacterial toxins <br />IgE – accelerates local inflammation <br />IgD – found on the surface of B cells <br />IgM – first type secreted after antigen arrives <br />IgA – primarily found in glandular sec <br />Primary and secondary antibody response <br />Primary response <br />Takes about two weeks to develop <br />The Lymphatic System and Immunity <br />Produced by plasma cells <br />Secondary response <br />Rapid increase in IgG <br />Maximum antibody titer app <br />Figure 22.22 The Primary and Secondary Immune Responses <br />Figure 22.23 An Integrated Summary of the Immune Response <br />Figure 22.25 The Course of the Body’s Response to Bacterial Infection <br />Focus on Hormones of the Immune System <br />Interleukins <br />Increase T cell sensitivity <br />Stimulate B cell activity, plasma formation, and antibody production <br />Enhance nonspecific defenses <br />Moderate the immune system <br />Interferons <br />Tumor Necrosis Factors (TNFs) slow tumor growth <br />Colony Stimulating Factors (CSFs) <br />SECTION 22-7 Normal and Abnormal Resistance <br />Development of the Immune Response <br />Immunological competence <br />The ability to demonstrate an immune response after exposure to an antigen <br />Fetuses receive immunity from the maternal bloodstream <br />Infants acquire immunity following exposure <br />Immune disorders <br />Autoimmune disorders <br />Immune response mistakenly targets normal cells <br />Immunodeficiency diseases <br />Immune system does not develop properly or is blocked <br />Allergies <br />Inappropriate or excessive immune response to allergens <br />Immediate hypersensitivity (type I) <br />Cytotoxic reactions (type II) <br />Immune complex disorders (type III) <br />Delayed hypersensitivity (type IV) <br />Anaphylaxis <br />Circulating allergen affects mast cells throughout body <br />Figure 22.26 The Mechanism of Anaphylaxis <br />Stress and the immune response <br />Interleukin-1 released by active macrophages <br />Triggers release of ACTH resulting in glucocorticoid release <br />Moderates the immune response <br />Lowers resistance to disease <br />Stress can cause the following: <br />Depression of the inflammatory response <br />Phagocytic reduction <br />Inhibition of interleukin secretion <br />SECTION 22-8 Aging and the Immune Response <br />With age <br />Immune system becomes less effective <br />Increased susceptibility to infection <br />Immune surveillance declines <br />You should now be familiar with: <br />The structure and function of lymphatic cells, tissues and organs <br />The body’s nonspecific defenses and the components and mechanisms of each <br />Specific resistance, cell-mediated immunity and antibody mediated immunity <br />The role of the T cell, B cell and antibodies in specific immunity <br />The origin, development, activation and regulation of normal resistance to disease <br />The effects of stress and aging on the immune system <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969266392398832?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692589531511942004-11-05T14:09:00.000-08:002004-11-05T14:09:49.533-08:00Chapter 22, part 3 <br />The Lymphatic System and Immunity <br />SECTION 22-4 Specific Defenses <br />Forms of immunity <br />Innate immunity <br />Genetically determined <br />Present at birth <br />Acquired immunity <br />Not present at birth <br />Achieved by exposure to antigen <br />Active immunity <br />Passive immunity <br />Figure 22.14 Types of Immunity <br />Properties of immunity <br />Specificity – activated by and responds to a specific antigen <br />Versatility – is ready to confront any antigen at any time <br />Memory – "remembers" any antigen it has encountered <br />Tolerance – responds to foreign substances but ignores normal tissues <br />The immune system response <br />Antigen triggers an immune response <br />Activates T cells and B cells <br />T cells are activated after phagocytes exposed to antigen <br />T cells attack the antigen and stimulate B cells <br />Activated B cells mature and produce antibody <br />Antibody attacks antigen <br />Figure 22.15 An Overview of the Immune Response <br />SECTION 22-5 T cells and Cell-mediated Immunity <br />Major types of T cells <br />Cytotoxic T cells (TC) – attack foreign cells <br />Helper T cells (TH) – activate other T cells and B cells <br />Suppressor T cells (TS) – inhibit the activation of T and B cells <br />Antigen presentation <br />Antigen-glycoprotein combination appears on a cell membrane <br />Called MHC proteins (Major Histocompatibility Complex) <br />Coded for by genes of the MHC <br />T-cells sensitive to the antigen are activated upon contact <br />MHC classes <br />Class I – found on all nucleated cells <br />Class II – found on antigen presenting cells and lymphocytes <br />Lymphocytes respond to antigens bound to either class I or class II MHC proteins <br />Antigen recognition <br />T cell membranes contain CD markers <br />CD3 markers present on all T cells <br />CD8 markers on cytotoxic and suppressor T cells <br />CD4 markers on helper T cells <br />Figure 22.16 Antigens and MHC Proteins <br />Figure 22.16 Antigens and MHC Proteins <br />Figure 22.16 Antigens and MHC Proteins <br />Activation of CD8 cells <br />Responds quickly giving rise to other T cells <br />Cytotoxic T cells – seek out and destroy abnormal cells <br />lymphotoxin <br />Memory TC cells – function during a second exposure to antigen <br />Suppressor T cells – suppress the immune response <br />Figure 22.17 Antigen Recognition and the Activation of Cytotoxic T Cells <br />Figure 22.17 Antigen Recognition and the Activation of Cytotoxic T Cells <br />Activation of CD4 T cells by antigens presented on class II MHC proteins <br />Produces helper T cells and memory T cells <br />Activated helper T cells <br />Secrete lymphokines that coordinate specific and nonspecific defenses <br />Enhance nonspecific defenses <br />Stimulate the activity of NK cells <br />Promote activation of B cells <br />Figure 22.18 Antigen Recognition and Activation of Helper T cells <br />Figure 22.19 A Summary of the Pathways of T Cell Activation <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969258953151194?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692521938253732004-11-05T14:08:00.000-08:002004-11-05T14:08:41.936-08:00Chapter 22, part 2 <br />The Lymphatic System and Immunity <br />The Thymus <br />Located behind sternum in anterior mediastinum <br />Capsule <br />Two lobes <br />Divided into lobules, each with a cortex and medulla <br />Cortical lymphocytes surrounded by reticular endothelial cells <br />Maintain blood–thymus barrier <br />Secretes thymic hormones: thymosins, thymopoietins, and thymulin <br />Figure 22.8 The Thymus <br />The Spleen <br />Largest mass of lymphoid tissue <br />Cellular components form pulp <br />Red pulp contains RBC <br />White pulp similar to lymphoid nodules <br />Spleen functions include <br />Removal of abnormal blood cells and other blood components <br />Storage of iron <br />Initiation of the specific immune response <br />Figure 22.9 The Spleen <br />Lymphatic system and body defenses <br />Nonspecific defenses <br />Do not distinguish one type of threat from another <br />7 types <br />Specific defenses <br />Protect against particular threats <br />Depend upon the activation of lymphocytes <br />SECTION 22-3 Nonspecific Defenses <br />Nonspecific Defenses, Physical barriers <br />Keep hazardous organisms outside the body <br />Includes hair, epithelia, secretions of integumentary and digestive systems <br />Figure 22.10 Nonspecific Defenses (Part 1 - Physical Barriers) <br />Nonspecific Defenses, Phagocytes <br />Remove cellular debris and respond to invasion by foreign pathogens <br />Monocyte-macrophage system - Fixed and free <br />Microphages – Neutrophils and eosinophils <br />Move by diapedesis <br />Exhibit chemotaxis <br />Figure 22.10 Nonspecific Defenses(Part 2 - Phagocytes) <br />Nonspecific Defenses, Immunological surveillance <br />Constant monitoring of normal tissue by NK cells <br />NK cells <br />Recognize cell surface markers on foreign cells <br />Destroy cells with foreign antigens <br />NK cell activation <br />Recognition of unusual surface proteins <br />Rotation of the Golgi toward the target cell and production of perforins <br />Release of perforins by exocytosis <br />Interaction of perforins causing cell lysis <br />Figure 22.10 Nonspecific Defenses(Part 3 - Immunological Surveillance) <br />Figure 22.11 How Natural Killer Cells Kill Cellular Targets <br />Nonspecific Defenses, Interferons (cytokines) <br />Small proteins released by virally infected cells <br />Trigger the production of antiviral proteins <br />Three major types of interferons are: <br />Alpha– produced by leukocytes and attract/stimulate NK cells <br />Beta– secreted by fibroblasts causing slow inflammation <br />Gamma – secreted by T cells and NK cells stimulate macrophage activity <br />Figure 22.10 Nonspecific Defenses(Part 4 - Interferons) <br />Nonspecific Defenses, Complement system <br />Cascade of ~11 plasma complement proteins (C) <br />Destroy target cell membranes <br />Stimulate inflammation <br />Attract phagocytes <br />Enhance phagocytosis <br />Complement proteins interact with on another via two pathways <br />Classical <br />Alternative <br />Figure 22.10 Nonspecific Defenses(Part 5 - Complement System) <br />Figure 22.12 Complement Activation <br />Nonspecific Defenses, Inflammation <br />Localized tissue response to injury producing <br />Swelling <br />Redness <br />Heat <br />Pain <br />Effects of inflammation include <br />Temporary repair of injury <br />Slowing the spread of pathogens <br />Mobilization of local, regional, and systemic defenses <br />Figure 22.10 Nonspecific Defenses(Part 6 - Inflammatory Response) <br />Figure 22.13 Inflammation <br />Nonspecific Defenses, Fever <br />Maintenance of a body temperature above 37.2oC (99oF) <br />Pyrogens reset the hypothalamic thermostat and raise body temperature <br />Pathogens, toxins, antigen-antibody complexes can act as pyrogens <br />Figure 22.10 Nonspecific Defenses(Part 7 - Fever) <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969252193825373?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1099692446514329452004-11-05T14:07:00.000-08:002004-11-05T14:07:26.513-08:00Learning Objectives <br />Describe the structure and function of lymphatic cells, tissues and organs <br />List the body’s nonspecific defenses and describe the components and mechanisms of each <br />Define specific resistance and distinguish between cell-mediated immunity and antibody mediated immunity <br />Learning Objectives <br />Discuss the role of the T cell, B cell and antibodies in specific immunity <br />Describe the origin, development, activation and regulation of normal resistance to disease <br />Discuss the effects of stress and aging on the immune system <br />SECTION 22-1 An Overview of the Lymphatic System and Immunity <br />lymphatic system <br />The lymphatic system <br />Contains cells, tissues, and organs responsible for defending the body <br />Lymphocytes resist infection and disease by responding to <br />Invading pathogens such as bacteria or viruses <br />Abnormal body cells such as cancer cells <br />Foreign proteins such as toxins <br />Figure 22.1 The Components of the Lymphatic System <br />SECTION 22-2 Organization of the Lymphatic System <br />The lymphatic system consists of <br />Lymph <br />Lymphatic vessels <br />Lymphoid tissues and organs <br />Lymphocytes and supporting phagocytic cells <br />Functions of lymphatic system <br />Primary function is production, maintenance, and distribution of lymphocytes <br />Lymphocytes must: <br />Detect where problems exist <br />Be able to reach the site of injury or infection <br />Lymphatic vessels include <br />Lymphatic capillaries <br />Small lymphatic vessels <br />Major lymph-collecting vessels <br />Figure 22.2 Lymphatic Capillaries <br />Figure 22.3 Lymphatic Vessels and Valves <br />Major lymph-collecting vessels <br />Superficial and deep lymphatics <br />Thoracic duct <br />Cisterna chyli <br />Right lymphatic duct <br />Figure 22.4 The Relationship between the Lymphatic Ducts and the Venous System <br />Figure 22.4 The Relationship between the Lymphatic Ducts and the Venous System <br />Figure 22.4 The Relationship between the Lymphatic Ducts and the Venous System <br />Lymphocytes <br />Three classes of lymphocytes <br />T (thymus dependent) cells <br />B (bone marrow-derived) cells <br />NK (natural killer) cells <br />Lymphocyte production (lymphopoiesis) <br />Involves bone marrow, thymus, and peripheral lymphoid tissue <br />B cells and NK cells mature in bone marrow <br />T cells mature in the thymus <br />Figure 22.5 The Derivation and Distribution of Lymphocytes <br />Lymphoid tissue <br />Connective tissue dominated by lymphocytes <br />Lymphoid nodules <br />Lymphocytes densely packed in areolar tissue <br />Found in the respiratory, digestive, and urinary tracts <br />MALT (mucosa-associated lymphoid tissue) <br />Collection of lymphoid tissues linked with the digestive system <br />Figure 22.6 Lymphoid Nodules <br />Lymphoid organs <br />Lymph nodes – function in the purification of lymph <br />Afferent lymphatics – carry lymph to nodes <br />Efferent lymphatics – carry lymph from nodes <br />Deep cortex dominated by T cells <br />Outer cortex and medulla contains B cells <br />Figure 22.7 The Structure of a Lymph Node <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109969244651432945?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1098394031192085722004-10-21T14:26:00.000-07:002004-10-21T14:27:11.193-07:00Chapter 3, part 1 <br />An Introduction to The Cellular Level of Organization <br />Learning Objectives <br />List the main points of the cell theory. <br />Describe the chief structural features of the cell membrane. <br />Describe the organelles of a typical cell, and give their specific functions. <br />Summarize the process of protein synthesis. <br />Describe the various transport mechanisms used by cells, and relate this to the transmembrane potential. <br />Describe the cell life cycle, mitosis and cellular differentiation. <br />SECTION 3-1 An Introduction to Cells <br />The cell theory states: <br />Cells are the building blocks of all plants and animals <br />Cells are produced by the division of preexisting cells <br />Cells are the smallest units that perform all vital physiological functions <br />Each cell maintains homeostasis at the cellular level <br />Homeostasis at higher levels reflects combined, coordinated action of many cells <br />Figure 3.1 The Diversity of Cells in the Human Body <br />Cell biology <br />Cytology, the study of the structure and function of cells <br />The human body contains both somatic and sex cells <br />Figure 3.2 The Anatomy of a Representative Cell <br />A typical cell <br />Is surrounded by extracellular fluid, which is the interstitial fluid of the tissue <br />Has an outer boundary called the cell membrane or plasma membrane <br />SECTION 3-2 The Cell Membrane <br />Cell membrane functions include: <br />Physical isolation <br />Regulation of exchange with the environment <br />Structural support <br />Figure 3.3 The Cell Membrane <br />The cell membrane is a phospholipid bilayer with proteins, lipids and carbohydrates. <br />Membrane proteins include: <br />Integral proteins <br />Peripheral proteins <br />Anchoring proteins <br />Recognition proteins <br />Receptor proteins <br />Carrier proteins <br />Channels <br />Figure 3.4 Membrane proteins <br />Membrane carbohydrates form the glycocalyx <br />Proteoglycans <br />Glycolipids <br />Glycoproteins <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109839403119208572?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com1tag:blogger.com,1999:blog-7191541.post-1098393896810145392004-10-21T14:24:00.000-07:002004-10-21T14:24:56.810-07:00Chapter 18, part 3 <br />The Endocrine System <br />SECTION 18-6 The Adrenal Glands <br />Adrenal cortex <br />Manufactures steroid hormones (corticosteroids) <br />Cortex divided into three layers <br />Zona glomerulosa (produces mineralocorticoids) <br />Zona fasciculate (produces glucocorticoids) <br />Zona reticularis (produces androgens) <br />Figure 18.16 The Adrenal Gland <br />Figure 18.17 Adrenal Abnormalities <br />Adrenal medulla <br />Produces epinephrine (~75 - 80%) <br />Produces norepinephrine (~25-30%) <br />SECTION 18-7 The Pineal Gland <br />Pineal gland <br />Contains pinealocytes <br />Synthesize melatonin <br />Suggested functions include inhibiting reproductive function, protecting against damage by free radicals, setting circadian rhythms <br />SECTION 18-1 The Pancreas <br />The pancreatic islets <br />Clusters of endocrine cells within the pancreas called Islets of Langerhans or pancreatic islets <br />Alpha cells secrete glucagons <br />Beta cells secrete insulin <br />Delta cells secrete GH-IH <br />F cells secrete pancreatic polypeptide <br />Figure 18.18 The Endocrine Pancreas <br />Insulin and glucagon <br />Insulin lowers blood glucose by increasing the rate of glucose uptake and utilization <br />Glucagon raises blood glucose by increasing the rates of glycogen breakdown and glucose manufacture by the liver <br />Figure 18.19 The Regulation of Blood Glucose Concentrations <br />SECTION 18-9 The Endocrine Tissues of Other Systems <br />The intestines <br />Produce hormones important to the coordination of digestive activities <br />The kidneys <br />Produce calcitriol and erythropoietin (EPO) and the enzyme rennin <br />Calcitriol = stimulates calcium and phosphate ion absorption along the digestive tract <br />EPO stimulates red blood cell production by bone marrow <br />Renin converts angiotensinogen to angiotensin I <br />Angiotensin I converted to angiotensin II in the lungs <br />Stimulates adrenal production of aldosterone <br />Stimulates pituitary gland release of ADH <br />Promotes thirst <br />Elevates blood pressure <br />Figure 18.20 Endocrine Functions of the Kidneys <br />Figure 18.20 Endocrine Functions of the Kidneys <br />The heart <br />Specialized muscle cells produce natriuretic peptides when blood pressure becomes excessive <br />Generally oppose actions of angiotensin II <br />The thymus <br />Produces thymosins <br />Help develop and maintain normal immune defenses <br />The gonads <br />Interstitial cells of the testes produce testosterone <br />Most important sex hormone in males <br />In females, oocytes develop in follicles <br />Follicle cells produce estrogens <br />After ovulation, the follicle cells form a corpus luteum that releases a mixture of estrogens and progesterone <br />Adipose tissues secrete <br />Leptin, a feedback control for appetite <br />Resistin, which reduces insulin sensitivity <br />SECTION 18-10 Patterns of Hormonal Interaction <br />Hormones often interact, producing <br />Antagonistic (opposing) effects <br />Synergistic (additive) effects <br />Permissive effects (one hormone is required for the other to produce its effect) <br />Integrative effects (hormones produce different but complimentary results) <br />Hormones and growth <br />Normal growth requires the interaction of several endocrine organs <br />Six hormones are important <br />GH <br />Thyroid hormones <br />Insulin <br />PTH <br />Calcitriol <br />Reproductive hormones <br />Hormones and stress <br />Stress = any condition that threatens homeostasis <br />GAS (General Adaptation Syndrome) is our bodies response to stress-causing factors <br />Three phases to GAS <br />Alarm phase (immediate, fight or flight, directed by the sympathetic nervous system) <br />Resistance phase (dominated by glucocorticoids) <br />Exhaustion phase (breakdown of homeostatic regulation and failure of one or more organ systems) <br />Figure 18.21 The General Adaptation Syndrome <br />Figure 18.21 The General Adaptation Syndrome <br />Figure 18.21 The General Adaptation Syndrome <br />Hormones and behavior <br />Many hormones affect the CNS <br />Changes in the normal mixture of hormones significantly alters intellectual capabilities, memory, learning and emotional states <br />SECTION 18-11 Aging and Hormone Production <br />Endocrine system <br />Few functional changes with age <br />Chief change is a decline in concentration of reproductive hormones <br />You should now be familiar with: <br />The major chemical classes and general mechanisms of hormones. <br />The location and structure of the pituitary gland, and its structural and functional relationships with the hypothalamus. <br />The location and structure of each of the endocrine glands. <br />The hormones produced by each of the endocrine glands, and the functions of those hormones. <br />You should now be familiar with: <br />The functions of the hormones produced by the kidneys, heart, thymus, testes, ovaries and adipose tissue. <br />How hormones interact to produce coordinated physiological responses. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109839389681014539?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1098393803850252542004-10-21T14:23:00.000-07:002004-10-21T14:23:23.850-07:00Chapter 18, part 2 <br />The Endocrine System <br />Hypophyseal portal system <br />All blood entering the portal system will reach the intended target cells before returning to the general circulation <br />Figure 18.7 The Hypophyseal Portal System <br />Figure 18.8 Feedback control of Endocrine Secretion <br />Figure 18.8 Feedback control of Endocrine Secretion <br />Hormones of the adenohypophysis <br />Thyroid stimulating hormone (TSH) <br />Triggers the release of thyroid hormones <br />Thyrotropin releasing hormone promotes the release of TSH <br />Adrenocorticotropic hormone (ACTH) <br />Stimulates the release of glucocorticoids by the adrenal gland <br />Corticotrophin releasing hormone causes the secretion of ACTH <br />Hormones of the adenohypophysis <br />Follicle stimulating hormone (FSH) <br />Stimulates follicle development and estrogen secretion in females and sperm production in males <br />Leutinizing hormone (LH) <br />Causes ovulation and progestin production in females and androgen production in males <br />Gonadotropin releasing hormone (GNRH) promotes the secretion of FSH and LH <br />Hormones of the adenohypophysis <br />Prolactin (PH) <br />Stimulates the development of mammary glands and milk production <br />Growth hormone (GH or somatotropin) <br />Stimulates cell growth and replication through release of somatomedins or IGF <br />Growth-hormone releasing hormone (GH-RH) <br />Growth-hormone inhibiting hormone (GH-IH) <br />Melanocyte stimulating hormone (MSH) <br />May be secreted by the pars intermedia during fetal development, early childhood, pregnancy or certain diseases <br />Stimulates melanocytes to produce melanin <br />The posterior lobe of the pituitary gland (neurohypophysis) <br />Contains axons of hypothalamic nerves <br />neurons of the supraoptic nucleus manufacture antidiuretic hormone (ADH) <br />Decreases the amount of water lost at the kidneys <br />Elevates blood pressure <br />The posterior lobe of the pituitary gland (neurohypophysis) <br />Neurons of the paraventricular nucleus manufacture oxytocin <br />Stimulates contractile cells in mammary glands <br />Stimulates smooth muscle cells in uterus <br />Figure 18.9 Pituitary Hormones and Their Targets <br />SECTION 18-4 The Thyroid Gland <br />The thyroid <br />Lies near the thyroid cartilage of the larynx <br />Two lobes connected by an isthmus <br />Figure 18.11 The Thyroid Gland <br />Figure 18.11 The Thyroid Gland <br />Thyroid follicles and thyroid hormones <br />Thyroid gland contains numerous follicles <br />Release several hormones such as thyroxine (T4) and triiodothyronine (T3) <br />Thyroid hormones end up attached to thyroid binding globulins (TBG) <br />Some are attached to transthyretin or albumin <br />Figure 18.12 The Thyroid Follicles <br />Figure 18.12 The Thyroid Follicles <br />Thyroid hormones <br />Held in storage <br />Bound to mitochondria, thereby increasing ATP production <br />Bound to receptors activating genes that control energy utilization <br />Exert a calorigenic effect <br />Cells of the thyroid gland <br />C cells produce calcitonin <br />Helps regulate calcium concentration in body fluids <br />Figure 18.13 Thyroid Disorders <br />SECTION 18-5 The Parathyroid Glands <br />Four parathyroid glands <br />Embedded in the posterior surface of the thyroid gland <br />Chief cells produce parathyroid hormone (PTH) in response to lower than normal calcium concentrations <br />Parathyroid hormones plus calcitriol are primary regulators of calcium levels in healthy adults <br />Figure 18.14 The Parathyroid Glands <br />Figure 18.15 The Homeostatic Regulation of Calcium Ion Concentrations <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109839380385025254?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1097875175736254842004-10-15T14:19:00.000-07:002004-10-15T14:19:35.736-07:00Chapter 2, part 1 <br />The Chemical Level of Organization <br />Learning Objectives <br />Describe an atom and compare the ways atoms combine to form molecules. <br />Distinguish among the types of chemical reactions that are important to physiology. <br />Describe the role of enzymes in metabolism. <br />Distinguish between organic and inorganic compounds. <br />Explain the importance of water, pH and buffers to living systems. <br />Discuss the structures and functions of carbohydrates, lipids, proteins, nucleic acids and high energy compounds. <br />SECTION 2-1 Atoms, Molecules and Bonds <br />Atoms are the smallest stable units of matter <br />Subatomic particles <br />Protons = positive charge; weight of approximately 1 Dalton <br />Neutrons = no charge; weight similar to protons <br />Electrons = negative charge; weigh 1/1836th Dalton <br />Protons and neutrons are found in the nucleus; electrons occupy electron cloud <br />Atomic number = proton number; atomic mass = protons and neutrons <br />Isotopes are elements with similar numbers of protons but different numbers of neutron <br />Figure 2.1 Hydrogen Atoms <br />Electrons occupy a series of energy levels or electron shells. <br />The outermost electron shell determines the reactivity of the element. <br />Figure 2.2 Atoms and Energy Levels <br />Atoms combine through chemical reactions <br />Molecule = a chemical structure consisting of molecules held together by covalent bonds <br />Compound = a chemical substance composed of atoms of two or more elements <br />There are three types of bond: Ionic, covalent, and hydrogen <br />Ionic = attraction between positive cations and negative anions <br />Figure 2.3 Ionic Bonding <br />Covalent bonds exist between atoms that share electrons to form a molecule <br />Double covalent bond <br />Non-polar covalent bond <br />Polar covalent bond <br />Hydrogen bonds are weak forces that affect the shape and properties of compounds <br />Polar covalent bonds that occur when hydrogen covalently bonds with another element <br />Figure 2.5 Polar Covalent Bonds and the Structure of Water <br />Figure 2.6 Hydrogen Bonds <br />Matter and chemical notation <br />Matter can exist as a solid, liquid or gas <br />Depends on the interaction of the component atoms or molecules <br />Molecular weight is the sum of the atomic weights of the component atoms <br />Chemical notation <br />Short-hand that describes chemical compounds and reactions <br />See table 2.2 for examples of chemical notation <br />SECTION 2-2 Chemical Reactions <br />A chemical reaction occurs when reactants combine to generate one or more products <br />All chemical reactions in the body constitutes metabolism <br />Metabolism provides for the capture, storage and release of energy <br />Basic energy concepts <br />Work = movement of an object or change in its physical structure <br />Energy = the capacity to perform work <br />Kinetic energy is energy of motion <br />Potential energy is stored energy resulting from position or structure <br />Conversions are not 100% efficient, resulting in release of heat <br />Metabolism <br />Types of reaction <br />Decomposition <br />Synthesis <br />Exchange <br />Metabolism is the sum of all reactions <br />Through catabolism cells gain energy (break down of complex molecules) <br />Anabolism uses energy (synthesis of new molecules) <br />Reversible reactions <br />All reactions are theoretically reversible <br />At equilibrium the rates of two opposing reactions are in balance <br />Anabolism = catabolism <br />Enzymes, energy and chemical reactions <br />Activation energy is the amount of energy needed to begin a reaction <br />Enzymes are catalysts <br />Reduce energy of activation without being permanently changed or used up <br />Promote chemical reactions <br />Figure 2.7 Enzymes and Activation Energy <br />SECTION 2-3 Inorganic Compounds <br />Nutrients and Metabolites <br />Nutrients are essential chemical compounds obtained from the diet <br />Metabolites are molecules synthesized or broken down inside the body <br />These can be classified as organic or inorganic compounds <br />Organic compounds have carbon and hydrogen as their primary structural component <br />Inorganic compounds are not primarily carbon and hydrogen <br />Water and its properties <br />Water is the most important constituent of the body <br />Solution is a uniform mixture of two or more substances <br />Solvent is the medium in which molecules of solute are dispersed <br />Water is the solvent in aqueous solutions <br />Figure 2.8 Water molecules and solutions <br />Electrolytes undergo ionization <br />Compounds that interact readily with water are hydrophilic <br />Compounds that do not interact with water are hydrophobic <br />pH is a measure of the concentration of hydrogen ions solution <br />Neutral <br />Acidic <br />Basic <br />Acids and Bases <br />Acids release hydrogen ions into solution <br />Bases remove hydrogen ions from solution <br />Strong acids and strong bases ionize completely <br />Weak acids and weak bases do not ionize <br />Figure 2.9 pH and Hydrogen Ion Concentration <br />Salts and buffers <br />Salt = an electrolyte whose cation is not hydrogen and whose anion is not hydroxide <br />Buffers remove or replace hydrogen ions in solution <br />Buffer systems maintain the pH of body fluids <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109787517573625484?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1097874890987799982004-10-15T14:14:00.000-07:002004-10-15T14:14:50.986-07:00Here is 18-1. More detail to follow in class <br /> <br />Chapter 18, part 1 <br />The Endocrine System <br />Learning Objectives <br />Compare the major chemical classes and general mechanisms of hormones. <br />Describe the location and structure of the pituitary gland, and explain its structural and functional relationships with the hypothalamus. <br />Describe the location and structure of each of the endocrine glands. <br />Learning Objectives <br />Identify the hormones produced by each of the endocrine glands and specify the functions of those hormones. <br />Describe the functions of the hormones produced by the kidneys, heart, thymus, testes, ovaries and adipose tissue. <br />Explain how hormones interact to produce coordinated physiological responses. <br />SECTION 18-1 Intercellular Communication <br />Endocrine versus Nervous system <br />Nervous system performs short term crisis management <br />Endocrine system regulates long term ongoing metabolic <br />Endocrine communication is carried out by endocrine cells releasing hormones <br />Alter metabolic activities of tissues and organs <br />Target cells <br />Paracrine communication involves chemical messengers between cells within one tissue <br />SECTION 18-2 An Overview of the Endocrine System <br />Endocrine system <br />Includes all cells and endocrine tissues that produce hormones or paracrine factors <br />Figure 18.1 The Endocrine System <br />Hormone structure <br />Amino acid derivatives <br />Structurally similar to amino acids <br />Peptide hormones <br />Chains of amino acids <br />Lipid derivatives <br />Steroid hormones and eicosanoids <br />Figure 18.2 A Structural Classification of Hormones <br />Hormones can be <br />Freely circulating <br />Rapidly removed from bloodstream <br />Bound to transport proteins <br />Mechanisms of hormone action <br />Receptors for catecholamines, peptide hormones, eicosanoids are in the cell membranes of target cells <br />Thyroid and steroid hormones cross the membrane and bind to receptors in the cytoplasm or nucleus <br />Figure 18.3 G Proteins and Hormone Activity <br />Figure 18.4 Hormone Effects on Gene Activity <br />Control of endocrine activity <br />Endocrine reflexes are the counterparts of neural reflexes <br />Hypothalamus regulates the activity of the nervous and endocrine systems <br />Secreting regulatory hormones that control the anterior pituitary gland <br />Releasing hormones at the posterior pituitary gland <br />Exerts direct neural control over the endocrine cells of the adrenal medullae <br />Figure 18.5 Three Methods of Hypothalamic Control over the Endocrine System <br />SECTION 18-3 The Pituitary Gland <br />Hypophysis <br />Releases nine important peptide hormones <br />All nine bind to membrane receptors and use cyclic AMP as a second messenger <br />Figure 18.6 The Anatomy and Orientation of the Pituitary Gland <br />The anterior lobe (adenohypophysis) <br />Subdivided into the pars distalis, pars intermedia and pars tuberalis <br />At the median eminence, neurons release regulatory factors through fenestrated capillaries <br />Releasing hormones <br />Inhibiting hormones <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109787489098779998?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1097183293155476692004-10-07T14:07:00.001-07:002004-10-07T14:08:13.156-07:00SECTION 17-4 Equilibrium and Hearing <br />Hearing <br />The special sense of hearing and equilibrium are provided by the inner ear which is a receptor complex located in the peterous part of the temporal bone of the skull <br />Equilibrium sensations inform us of the position of the head in space <br />Hearing enables us to detect and interpret sound waves <br />The basic mechanisms for both senses are hair cells, a mechanical sensors <br />The anatomy of the ear <br />Three anatomical regions <br />External ear <br />Middle ear <br />Inner ear <br />Both equilibrium and hearing are provided by receptors of the inner ear <br />Anatomy of the ear – External Ear: visible portion, collects and directs sound toward the middle ear: compostion <br />Auricle or pinnae surrounds the ear <br />External acoustic meatus ends on tympanic membrane <br />External ear <br />Includes the fleshy and cartilaginous auricle <br />This surrounds the external acoustic canal or ear canal <br />This is the passage way that ends on the tympanic membrane <br />Protective features found here in the form of ceruminous glands which produce cerumen <br />Figure 17.20 The Anatomy of the Ear <br />Middle ear <br />Communicates with pharynx via pharyngotympanic membrane <br />Middle ear encloses and protects the auditory ossicles <br />Figure 17.21 The Middle Ear <br />Middle Ear <br />Also called the tympanic cavity <br />It is separated from the external acoustic canal by the tympanic membrane <br />Communicates with the nasopharnyx through the auditory tube and the mastoid air cells <br />Also called the pharyngotympanic tube which permits equalization of air <br />Auditory Ossicles <br />Hammer <br />Anvil <br />Stirrup <br />What are the articulations? <br />Malleus attaches to the tympanic membrane <br />The stapes articulates on the oval window <br />How is sound carried? <br />It is the articulations of the hammer on the vibrating tympanic membrane that is passed to the stapes which moves up and down on the oval window <br />It is really a rocking motion on the stapes <br />This is a level design that amplifies sound because the tympanic membrane is heavier then the membrane of the oval window <br /> <br />What is the job of the inner ear? <br />The sense of equilibrium and hearing are provided by receptors of the inner ear <br />Remember that these receptors lie within a collection of fluid filled chambers known as the membranous labyrinth which is filled with an electrolytic soln called endolymph <br />Inner ear: bony labyrinth: function <br />Bony labyrinth surrounds and protects membranous labyrinth <br />Between the bony and membranous labyrinth is found perilymph (CSF) <br />What are the divisions of the bony labyrinth? <br />Vestibule: pair of membraneous sacs <br />Saccule <br />uticle <br />Semicircular canals <br />stimulated by rotation of the head <br />Cochlea <br />Provide the sense of hearing <br />Figure 17.22 The Inner Ear <br />Components of the inner ear: quick review: are what? <br />Vestibule contains the utricle and saccule <br />Semicircular canals contain the semicircular ducts <br />Cochlea contains the cochlear duct <br />Windows: two types: functions: <br />Round window separates the perilymph from the air spaces of the middle ear <br />Oval window connected to the base of the stapes <br />Basic receptors of inner ear are hair cells <br />Provide information about the direction and strength of stimuli <br />Receptors of the inner ear <br />These sensory receptors are called hair cells <br />These cells are surrounded by supporting cells and are monitored by sensory afferent fibers <br />The hair like structures have two components <br />Stereocilia: 80 – 100 present <br />Kinocilium: single large cilia <br />Only move when external forces push against them <br />What kind of information will these cilia provide? <br />Direction and strength of the mechanical stimulation and response varies depending on the location of the cilia <br />Types of stimulation can include: <br />Gravity or acceleration in the vestibule <br />Rotation in the semicircular canal <br />Sound in the cochlea <br /> <br />How is equilibrium information provided? <br />Provided by receptors of the vestibular complex <br />The information provided is based on rotational movements of the head <br />Thus the saccule and the utricle convey information with respect to gravity <br />They are stimulated by sudden acceleration (stop or start) <br /> <br />The semicircular ducts <br />Thus the sensory receptors are quiet during non movement <br />What is this movement? <br />The kinocilia and the sterocilia are embeded in the cupula <br />Cupula floats on the endolymph <br />The movement of ones head distorts the receptor processes <br />Movement is based on direction <br />When there is no further movement, the cupula returns to the rest position <br />Thus there is analysis of motion in three planes <br /> <br />What is the job of Utricle and Saccule? <br />Both provide information about equilibrium whether or not the body is stationary or moving <br />Equilibrium: The whole structure è otolith <br />Anterior, posterior and lateral semicircular ducts are continuous with the utricle <br />Each duct contains an ampulla with a gelatinous cupula and associated kinocilia and sterocilia (review) <br />Saccule and utricle connected by a passageway continuous with the endolymphatic duct <br />Terminates in the endolymphatic sac <br />Saccule and utricle have hair cells clustered in an oval structure called the maculae <br />Cilia contact the statoconia ( calcium carbonate crystals) <br />Figure 17.23 The Vestibular Complex <br />Figure 17.23 The Vestibular Complex <br />Figure 17.23 The Vestibular Complex <br />Vestibular neural pathway: How is monitoring achieved? <br />Hairs of the vestribular and semicircular ducts are monitored by sensory neurons located in the vestibular ganglia <br />Axons form the vestibular branch of the vestibular cocohlear nerve (VIII) <br />Synapses within the vestibular nuclei between the pons and the medulla oblongata <br />Job functions; 4 of them <br />Integrating sensory information about balance and equilibrium that arrives from both sides of the head <br />Relay information from the vestibular complex to the cerebellum <br />Relay information from the vestibular complexd to the cerebral cortex for a conscious position of position of head <br />Send motor commands to nuclei in brain stem and spinal cord <br /> <br />What kind of information is sent? <br />Reflexive motor commands that are issued are distributed to motor nuclei for cranial nerves III, IV, VI, and XI <br />Descend down the vestibularspinal tracts <br />Adjust muscle tone <br />Figure 17.24 Pathways for Equilibrium Sensation <br />Hearing <br />Cochlear duct lies between the vestibular duct and the tympanic duct <br />Hair cells of the cochlear duct lie within the Organ of Corti <br />Intensity is the energy content of a sound <br />Measured in decibels <br />Figure 17.25 The Cochlea <br />Figure 17.26 The Organ Of Corti <br />Hearing <br />The receptors of the cochlear duct provide the sense of hearing that enables us to detect soft sounds <br />Hair cells responsible for picking up this auditory sound <br />Location prevents them from responding to any other stimuli <br />Whole process is based on pressure waves <br />This is the fluctuations of perilymph which determine the frequency and intensity <br />Pathway of sound <br />Sound waves travel toward tympanic membrane, which vibrates <br />Auditory ossicles conduct the vibration into the inner ear <br />Tensor tympani and stapedius muscles contract to reduce the amount of movement when loud sounds arrive <br />Movement at the oval window applies pressure to the perilymph of the cochlear duct <br />Pressure waves distort basilar membrane <br />Hair cells of the Organ of Corti are pushed against the tectoral membrane <br />It is the distortion of the basiliar membrane pressing on the tectorial membrane that results in the generation of an action potential in the receptors <br />Figure 17.28 Sound and Hearing <br />Figure 17.29 Sound and Hearing <br />Neural pathway; location of the nerve fibers <br />Sensory neurons of hearing are located in the spiral ganglion of the cochlea <br />Afferent fibers form the cochlear branch of cranial nerve VIII <br />Synapse at the cochlear nucleus <br />The steps: <br />Sound waves arrive at the tympanic membrane <br />Tympanic membrane causes displacement of auditory ossciles <br />Stapes moves against the oval window <br />Pressure waves distort the basilar membrane <br />Vibration of the basilar membrane <br />Relay information along the afferent branch of the Vestibularcodhlear nerve VIII to the cochlear nucleus then crosses to opposite side of the brain to the inferior colliculus <br />Then to the thalamus and finally to the auditory cortex of the temporal lobe <br />You should now be familiar with: <br />The sensory organs of smell, and the olfactory pathways in the brain. <br />The accessory and internal structures of the eye, and their functions. <br />How light stimulates the production of nerve impulses, and the visual pathways. <br />The structures of the external and middle ear and how they function. <br />The parts of the inner ear and their roles in equilibrium and hearing. <br />The pathways for the sensations of equilibrium and hearing. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109718329315547669?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1096591686131217612004-09-30T17:47:00.000-07:002004-09-30T17:48:06.130-07:00Chapter 17, part 2 <br />The Special Senses <br />Fibrous tunic <br />Defined as the outermost layer of the eye <br />Provides mechanical support and protection <br />Serves as an attachment site for the extrinstic muscles of the eyes <br />Contain aids for focusing <br /> <br />Outer surface <br />Large part of the outer surface is called the sclera of the white of the eye <br />Composed of dense connective tissue containing collage and elastic fibers <br />Thickest over the posterior surface of the eye and thinnest on the anterior surface of the eye near the optic nerve <br />Six extrinsic eye muscles insert on the sclera of the eye <br /> <br /> <br />Sclera composition <br />Small blood vessels and nerves that penetrate into the internal structures of the eye <br />The cornea is continuous with the sclera and the border between the sclera and the cornea is called the limbus <br /> <br />Cornea composition <br />No blood vessels <br />Nutrients and oxygen are obtained from tears <br />Also has many free nerve endings <br />Vascular tunic <br />Composition: <br />Blood vessels <br />Lymph vessels <br />Intristic eye muscles <br /> <br />Function: <br />Provides a route for blood and lymph vessels <br />Regulates the amount of light that enters the eye <br />Secreting and reabsorbing the aqueous humor <br />Control the shape of the lens <br /> <br />More on composition <br />Iris <br />Ciliary body <br />choroid <br />Iris <br />Contains <br />Blood vessels <br />Pigment cells <br />Two layers of smooth muscle tissue which regulate the diameter of the pupil, these sphincter muscles are under autonomic control <br />Pupillary constrictor muscles <br />Pupillary dilator muscles <br /> <br />The body of the iris <br />High vascularized pigmented loose connective tissue <br />The anterior portion contains the melanocytes which are responsible for the color on the surface of the eye <br />Ciliary Body <br />The iris is anchored to the ciliary body at its periphery <br />This ciliary body begins at the junction of the cornea and the sclera and ends at the orta serrata <br />The bulk of this ciliary body consists of ciliary muscle <br />Suspensory ligaments attach to the ciliary processes <br /> <br /> <br />Choroid <br />Has an extensive capillary network that delivers oxygen to the retina <br /> <br />Neutral Tunic <br />Also called the retina <br />Inner most portion of the eye <br /> <br />Composition <br />Outer most layer called the pigment part <br />Inner most layer called the neural part <br />Job functions <br />Pigment part absorbs the light the passes through the neutral part and prevents light from bouncing back to the neural part <br />The neural part contains blood vessels and processes preliminary visual information <br />Extent of the layers <br />Pigment part extends over the ciliary body and iris <br />The neural part extend just to the orta serrata <br /> <br />Retina: organization: the photoreceptors <br />Retina contains rods and cones <br />Cones densely packed at fovea (center of the macula lutea) <br />Retinal pathway <br />Rods and cones synapse with 6 million bipolar neurons which pass on information to ganglion cells, to the brain via the optic nerve <br />Axons of ganglion cells converge at blind spot (optic disc) <br />Horizontal cells and amacrine cells modify the signal passed along the retinal neurons by facilitation or inhibition <br />What are the jobs of the rods and cones? <br />The rods do not discriminate colors of light <br />The cones provides us with color vision <br />Three cone types determine the color you see <br />Also give us sharper clear images <br />However, they require more intense light to be active <br /> <br />Rod and cone distribution <br />125 million rods are found along the periphery of the retina <br />6 million cones span the posterior surface <br />Most found near the macula lutea <br />This region contain NO rods! <br />The highest concentration of the cones occurs at the center of the muscula lutea and this region is called the fovea <br />Region of sharpest vision <br />Optic disc <br />The axons from 1 million ganglion cells converge on the optic disc <br />This disc is the origin of cranial nerve II which proceeds to the diencephalon <br />The central retinal artery and vein can be found here <br />The optic disc has no photoreceptors <br />This area of contact is called the blind spot <br /> <br />Chamber of the eye <br />Anterior cavity <br />Anterior chamber <br />Posterior chamber <br />Posterior chamber <br /> <br />Aqueous humor <br />A fluid which circulates within the anterior cavity passing from the posterior chamber to the anterior chamber through the pupil <br />Formed by cells of the ciliary processes <br />Similar to CSF <br />This creates intraocular pressure which forces the neural layer against the pigmented layer <br />Returns from the posterior chamber back to the anterior chamber by passing through the canal of Schlemm <br />This is then passed onto the veins of the sclera <br /> <br /> <br />Viterous Body <br />Posterior portion of the eye contains the viterous body <br />Gelatin like in structure <br />Stabilizes the shape of the eye <br />Additional physical support to the retina <br />Fluid is made up of collagen and proteoglycans (these resemble cellulose like materials) <br />Never replaced <br />Figure 17.6 The Organization of the Retina <br />Eye anatomy: pause and review <br />Ciliary body and lens divide the anterior cavity of the eye into posterior (vitreous) cavity and anterior cavity <br />Anterior cavity further divided <br />anterior chamber in front of eye <br />posterior chamber between the iris and the lens <br />Figure 17.8 The Circulation of Aqueous Humor <br />Fluids in the eye <br />Aqueous humor circulates within the eye <br />diffuses through the walls of anterior chamber <br />passes through canal of Schlemm <br />re-enters circulation <br />Vitreous humor fills the posterior cavity. <br />Not recycled – permanent fluid <br />Lens <br />Posterior to the cornea and forms anterior boundary of posterior cavity <br />Posterior cavity contains vitreous humor <br />Lens helps focus <br />Light is refracted as it passes through lens <br />Accommodation is the process by which the lens adjusts to focus images <br />Normal visual acuity is 20/20 <br />Figure 17.9 Image Formation <br />Figure 17.10 Accommodation <br />Figure 17.11 Visual Abnormalities <br />Visual physiology <br />Rods – respond to almost any photon <br />Cones – specific ranges of specificity <br />Figure 17.13 Rods and Cones <br />Photoreceptor structure <br />Outer segment with membranous discs <br />Narrow stalk connecting outer segment to inner segment <br />Light absorption occurs in the visual pigments <br />Derivatives of rhodopsin <br />Figure 17.14 Photoreception <br />Figure 17.14 Photoreception <br />Figure 17.15 Bleaching and Regeneration of Visual Pigments <br />Color sensitivity <br />Integration of information from red, blue and green cones <br />Colorblindness is the inability to detect certain colors <br />retinal adaptation <br />Dark adapted – most visual pigments are fully receptive to stimulation <br />Light adapted – pupil constricts and pigments bleached. <br />the visual pathway <br />Large M-cells monitor rods <br />Smaller more numerous P cells monitor cones <br />Figure 17.18 Convergence and Ganglion Cell Function <br />Seeing in stereo <br />Vision from the field of view transfers from one side to the other while in transit <br />Depth perception is obtained by comparing relative positions of objects from the two eyes <br />Figure 17.19 The Visual Pathways <br />Visual circadian rhythm <br />Input to suprachiasmic nucleus affects the function of the brainstem <br />Circadian rhythm ties to day-night cycle, and affects metabolic rates <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109659168613121761?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1096591332022861402004-09-30T17:37:00.000-07:002004-09-30T17:48:50.173-07:00Chapter 17, part 1 <br />The Special Senses <br />Learning Objectives <br />Describe the sensory organs of smell, and trace the olfactory pathways to their destination in the brain. <br />Identify the accessory and internal structures of the eye, and explain their function. <br />Explain how light stimulates the production of nerve impulses, and trace the visual pathways to their destination in the brain. <br />Describe the structures of the external and middle ear and explain how they function. <br />Learning Objectives <br />Describe the parts of the inner ear and their roles in equilibrium and hearing. <br />Trace the pathways for the sensations of equilibrium and hearing to their destinations in the brain. <br />SECTION 17-1 Olfaction <br />What is the composition <br />The sense of smell as defined as the process called olfaction <br />These organs are located in the nasal cavity on either side of the nasal septum <br />Composition <br />Two layers <br />Olfactory epithelium <br />Here are located the olfactory receptors <br />Basal cells <br />Stem cells or supporting cells <br /> <br />Where is this epithelium found? <br />Inferior surface of the cribriform plate <br />Superior portion of the perpendicular plate <br />Superior nasal conchae <br />Underlying portions contain the olfactory glands <br />Olfactory receptors <br />They are considered to be highly modified neurons <br />The exposed tip of the neuron forms a bulb which extends beyond the surface of the epithelium and extends into the mucus <br />Here the cilia are found and have exposed surfaces for picking up chemicals <br /> <br />Where does olfaction occur? <br />Occurs on the surface of the cilia <br />There are special receptors called odorant binding proteins <br />The chemicals which bring about the response are called an ordorant <br />Ordorants trigger a chemical response through secondary messengers <br /> <br />Olfactory pathways <br />It is believed that as few as four molecules can trigger an response <br />Not all information will reach the olfactory centers <br />There is significant olfactory central adaptation <br />There is two or more axons which bundle themselves together after they emerge from the cribiform plate and pass the cerebrum <br />They also reach the hypothalamus and limbic system <br />The olfactory information that is collected, does not synapse in the thalamus before it goes to the cerebrum <br />Olfactory Discrimination <br />2000 – 400 smells <br />All olfactory cells look the same <br />50 primary smells <br />Pattern of receptor activity are interpreted determine the "smell" <br />Pattern determination fails with age <br />Olfactory organs: Review <br />Contain olfactory epithelium with olfactory receptors, supporting cells, basal cells <br />Olfactory receptors are modified neurons <br />Surfaces are coated with secretions from olfactory glands <br />Olfactory reception involved detecting dissolved chemicals as they interact with odorant binding proteins <br />Figure 17.1 The Olfactory Organs <br />Olfaction <br />Olfactory pathways <br />No synapse in the thalamus for arriving information <br />Olfactory discrimination <br />Can distinguish thousands of chemical stimuli <br />CNS interprets smells by pattern of receptor activity <br />Olfactory receptor population shows considerable turnover <br />Number of receptors declines with age <br />SECTION 17-2 Gustation <br />The beginning: where do we find <br />Taste receptors are distributed over the surface of the tongue and the adjacent portions of the pharynx and the larynx <br />The most important ones are found on the tongue <br />Adults have 3000 taste buds <br />Where find on the tongue? Found everywhere on tongue? <br />Three types of lingual papillae <br />Filiform <br />Fungiform <br />Circumvallate <br /> <br />Filiform <br />No taste receptors found here <br />These provide friction to help move food along <br /> <br />Fungiform <br />Contains 5 taste buds <br /> <br />Cicumvallate <br />Largest of the papillae <br />Contains about 100 taste buds <br />Form a V with the posterior margin of the tongue <br /> <br />How are taste buds put together? <br />They are placed in recessed spaces to isolate them from the rest of contents of the rest of the mouth <br />There are four different cell types within a taste bud <br />Stage one are the basal cells for repair and replacement <br />Stage four are the gustratory cells which are responsible for the taste <br />Each taste bud has a pore for fluids to enter <br />Gustatory cells last only 10 days <br />Taste receptors Quick review <br />Clustered in taste buds <br />Associated with lingual and circumvallate papillae <br />Contain basal cells which appear to be stem cells <br />Gustatory cells extend taste hairs or cilia through a narrow taste pore <br />Figure 17.2 Gustatory Reception <br /> <br />Gustatory pathways <br />Taste buds are monitored by cranial nerves VII, IX, and X <br />Synapse within the solitary nucleus of the medulla oblongata and the medial lemniscus <br />There the neurons axons that carry somatic sensory information on touch, pressure, and proprioception <br />Then on to the thalamus and finally the primary sensory cortex <br />When is there a conception perception? <br />That of taste is produced as the information received is correlated with other sensory data <br />This includes information about texture of the food <br />Other data is carried by the V cranial nerve <br />Sensitive to taste is enhanced by olfaction <br /> <br />Gustatory discrimination <br />Primary taste sensations are defined as being: <br />Sweet, sour, salty, bitter <br />Receptors also exist for umami and water <br />Taste sensitivity shows significant individual differences, some of which are inherited <br />The number of taste buds declines with age <br />What is umani? <br />Pleasant taste depending on the presence of amino acids <br />They are found in the circumvalatte papillae <br /> <br />Water receptors? <br />Found in the pharynx <br />Processed in the hypothalamus <br />It is known that it affects the production of ADH <br /> <br />What is the mechanism of gustatory? <br />Dissolved chemicals must come in contact with receptors <br />Different receptors for different tastes <br />The net is always a stimulation of sensory neurons from the taste receptors that produce an graded potential <br />Taste receptors adapt slowly but there is central adaptation reduces your sensitivity to a new taste presented <br /> <br />How do we define this threshold? <br />Two conditions <br />For unpleasant taste, the receptors respond more quickly <br />Sour tastes respond quickly <br />Sweet of salty is responding slower <br />But more sensitive to bitter, quinine compds <br /> <br />SECTION 17-3 Vision <br />Accessory structures of the eye; the divisions <br />Job function: <br />protection, lubrication, and support <br />Eyelids (palpebrae) separated by the palpebral fissure <br />Eyelashes <br />Tarsal glands <br />Lacrimal apparatus <br />The eyelids <br />Also called the palprebra <br />Keeps the surface of the eye lubricated and free from dust and debris <br />Capable of tight closure <br />The palprebra fissure separates the upper and lower eyelids <br />The eyelids are connected at the median and lateral canthus <br /> <br />Eyelashes <br />The eyelashes prevent foreign matter from reaching the eye <br />Did you know that there are small mites growing on your eyelids <br />Think of the contain of eyelash liner as a growth chamber for these bugs <br /> <br />Eyelashes and lubrication <br />We find that along the inner margin of the lid is a gland called the tarsal gland <br />The oil prevents the lids from sticking together <br />There are also lacrimal glands that produce secretions that are gritty <br />All glands subject to infection <br /> <br />Function of Lubrication <br />Keeps the conjunctival surface clean and moist <br />Tears reduce friction and prevent bacterial infections <br />Provide nutrients and oxygen portions to the conjunctival epithelium <br /> <br />Lacrimal appratus construction <br />Lacrimal glands and associated ducts <br />Lacrimalcanaliculi <br />Lacrimal sac <br />Nasolacrimal duct <br />How are demands meet? <br />Nutrient and oxygen demands are met by diffusion from the lacrimal secretions <br />Lacrimal apparatus: function <br />Secretions from the lacrimal gland contain lysozyme <br />Provides the key incredients and most of the volume of the tears that bathe the conjunctival surface <br />Tears form in the lacrimal glands, wash across the eye and collect in the lacrimal lake <br />Then pass through the lacrimal punctae, lacrimal canaliculi, lacrimal sac and nasolacrimal duct when these secretions drain from the eye itself <br />What is produced? <br />About 1 mL of tears/day <br />These secretions then mix with oils from accessory glands and form and oil slick that assists in lubrication and the slowly of evaporation <br />What does blinking do? <br />Blinking provides a sweeping action across the surface of the eye <br />Figure 17.3 Eternal Features and Accessory Structures of the Eye <br />external structures of the eye <br />Conjunctiva covers most of inner portion of the eyelids and the outer surface of the eye <br />This is really a mucus membrane made of two parts: <br />Palpebral conjunctiva <br />Ocular conjunctive <br />What is the cornea? <br />Cornea is transparent anterior portion in which light passes through <br />The occur conjunctiva ends here <br />This is covered by corneal epithelium <br />What is conjunctivitis? <br />Pink eye <br />Damage to the conjunctival surface <br />Characterized by dilation of blood vessels deep to the conjunctival eipthelium <br />The eye <br />Three layers <br />Outer fibrous tunic <br />Sclera, cornea, limbus <br />Middle vascular tunic <br />Iris, ciliary body, choroid <br />Inner nervous tunic <br />Retina <br />Figure 17.4 The Sectional Anatomy of the Eye <br />Structures <br />Posterior cavity <br />Viterous humor <br />Contains the retinal <br />Anterior cavity <br />Aqueous humor <br />Orbial fat <br />internal structures of the eye <br />Ciliary body <br />Ciliary muscles and ciliary processes, which attach to suspensory ligaments of lens <br />Retina <br />Outer pigmented portion <br />Inner neural part <br />Rods and cones <br />Figure 17.4 The Sectional Anatomy of the Eye <br />Figure 17.5 The Pupillary Muscles <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109659133202286140?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1096220360110540532004-09-26T10:36:00.000-07:002004-09-26T10:39:20.110-07:00SECTION 16-3 The Parasympathetic Division <br />Parasympathetic division: <br />Preganglionic neurons in the brainstem and sacral segments of spinal cord <br />Ganglionic neurons in peripheral ganglia located within or near target organs <br />Figure 16.7 The Organization of the Parasympathetic Division of the ANS <br />Organization and anatomy of the parasympathetic division <br />Preganglionic fibers leave the brain as cranial nerves III, VI, IX, X <br />Sacral neurons form the pelvic nerves <br />Figure 16.8 The Distribution of Parasympathetic Innervation <br />Parasympathetic activation <br />Effects produced by the parasympathetic division <br />relaxation <br />food processing <br />energy absorption <br />Neurotransmitters and parasympathetic functions <br />All parasympathetic fibers release ACh <br />Short-lived response as ACH is broken down by AChE and tissue cholinesterase <br />Postsynaptic membranes have two kinds of receptors <br />Muscarinic <br />Ach receptors respond to the poison <br />Nicotinic <br />Ach receptors which respond to nicotine <br />SECTION 16-4 Interactions Between the Sympathetic and Parasympathetic Divisions <br />Sympathetic and parasympathetic divisions <br />Sympathetic <br />Widespread influence on visceral and somatic structures <br />Parasympathetic <br />Innervates only visceral structures serviced by cranial nerves or lying within the abdominopelvic cavity <br />Dual innervation = organs that receive input from both systems <br />Summary: parasympathetic division <br />Parasympathetic division includes cranial nerves III, VII, IX, and X and sacral segments S2 – S4 <br />Ganglion are located near target organs <br />Divisions are cholinergic <br />Effects are brief and site restricted <br /> <br />Anatomy of dual message delivery <br />Sympathetic and parasympathetic systems intermingle to form autonomic plexuses <br />Cardiac plexus <br />Pulmonary plexus <br />Esophageal plexus <br />Celiac plexus <br />Inferior mesenteric plexus <br />Hypogastric plexus <br />Figure 16.9 The Autonomic Plexuses <br />Comparison of the two divisions <br />Important physiological and functional differences exist <br />Figure 16.10 Summary: The Anatomical Differences between the Sympathetic and Parasympathetic Divisions <br />SECTION 16-5 Integration and Control of Autonomic Functions <br />Visceral reflexes <br />Visceral reflex arcs are the simplest function of the ANS <br />Long reflexes (interneurons) <br />Short reflexes (bypassing CNS) <br />Parasympathetic reflexes govern respiration, cardiovascular function and other visceral activities <br />Figure 16.11 Visceral Reflexes <br />Higher levels of autonomic control <br />Activity in the ANS is controlled by centers in the brainstem that deal with visceral functioning <br />Figure 16.12 Levels of Autonomic Control <br />SNS and ANS organized in parallel <br />Integration occurs at the brainstem and higher centers <br />Figure 16.13 A Comparison of Somatic and Autonomic Function <br />SECTION 16-6 High Order Functions <br />Higher order functions <br />Are performed by the cerebral cortex and involve complex interactions <br />Involve conscious and unconscious information processing <br />Are subject to modification and adjustment over time <br />Memory <br />Short term or long term <br />Memory consolidation is moving from short term to long term <br />Amnesia is the loss of memory due to disease or trauma <br />Figure 16.14 Memory Storage <br />Consciousness <br />Deep sleep, the body relaxes and cerebral cortex activity is low <br />REM sleep active dreaming occurs <br />The reticular activating system (RAS) is important to arousal and maintenance of consciousness <br />Figure 16.16 The Reticular Activating System <br />SECTION 16-7 Brain Chemistry and Behavior <br />Neurotransmitters and the brain <br />Neurotransmitters and brain function <br />Changes in balance between neurotransmitters can profoundly alter brain function <br />Personality and self-awareness <br />Characteristics of the brain as an integrated system rather than one specific component <br />SECTION 16-8 Aging and the Nervous System <br />Age-related changes <br />Reduction in brain size and weight <br />Reduction in the number of neurons <br />Decrease in blood flow to the brain <br />Changes in synaptic organization of the brain <br />Intracellular and extracellular changes in CNS neurons <br />You should now be familiar with: <br />The organization of the autonomic nervous system. <br />The structures and functions of the sympathetic and parasympathetic divisions of the ANS. <br />The mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. <br />The effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. <br />The hierarchy of interacting levels of control in the ANS. <br />How memories are created, stored and recalled. <br />The effects of aging on the nervous system. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109622036011054053?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974842185014402004-09-23T14:26:00.001-07:002004-09-26T10:26:34.410-07:00Learning Objectives <br />Compare the organization of the autonomic nervous system with the somatic nervous system. <br />Describe the structures and functions of the sympathetic and parasympathetic divisions of the ANS. <br />Describe the mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. <br />Describe the effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. <br />Learning Objectives <br />Describe the hierarchy of interacting levels of control in the ANS <br />Explain how memories are created, stored and recalled. <br />Summarize the effects of aging on the nervous system. <br />SECTION 16-1 An Overview of the ANS <br />General information <br />Neural Integration II: The Autonomic Nervous System and Higher Order Functions <br />There are going to be two major goals here, compare: <br />The neural interactions that direct motor output <br />The subdivisions of the ANS based on structural and functional patters <br /> <br />Common ground <br />Both the somatic and autonomic nervous systems are efferent that carry motor commands to the skeletal system <br />In the somatic nervous system the commands form the CNS exert direct control over the the skeletal muscle <br />In the ANS motor neurons of the CNS synapse on visceral motor neurons in autonomic ganglion and it is through the ganglion that control is exerted <br /> <br />More <br />The visceral motor neurons of the CNS are known as preganglionic neurons and the axons are called prehanglionic fibers <br />Those that leave the ganglion are called postganglionic fibers <br /> <br /> <br />Somatic or visceral information input <br />Input can trigger visceral reflexes and these motor commands are distributed by the ANS <br />ANS (review) <br />Coordinates cardiovascular, respiratory, digestive, urinary and reproductive functions <br />Preganglionic neurons in the CNS send axons to synapse on ganglionic neurons in autonomic ganglia outside the CNS <br />Divisions of the ANS <br />Most often the divisions have opposing effects <br />However, some divisions are only controlled by one of the divisions <br />Sympathetic division (thoracolumbar, "fight or flight") <br />Thoracic and lumbar segments <br />Parasympathetic division (craniosacral, "rest and repose") <br />Preganglionic fibers leaving the brain and sacral segments <br />A general statement <br />The parasympathetic nervous system dominates under resting conditions <br />And the sympathetic nervous system kicks in under times of stress <br /> <br />Eneteric nervous system <br />Generally local control over digestive properties <br />But the activity can also be influenced by both the sympathetic and parasympathetic divisions <br />SECTION 16-2 The Sympathetic Division <br />Sympathetic division anatomy <br />Preganglionic neurons between segments T1 and L2 <br />Ganglionic neurons in ganglia near vertebral column <br />The preganlionic fibers are short and the postganglionic fibers are long <br />The job is to prepare the body for fight of flight responses <br />Specialized neurons in adrenal glands <br />Parasympathetic division <br />The preganlionic fibers originate in the brain stem and the sacral segments of the spinal cord <br />They synapse in ganglion which are close to the target organ <br />This means that the preganlionic fibers are long and the postganglionic fibers are short <br />Job is to conserve energy <br />This means that if you consume a heavy meals, the activity is for digestions, absorption, and waste removal <br />Figure 16.3 The Organization of the Sympathetic Division of the ANS <br />Sympathetic division <br />The division consists of preganglionic neurons that are located between segments T1 and L2 of the spinal cord <br />The cell bodies are located in the gray matter of the lateral gray horns of their axons axons enter the ventral root at three segments <br /> <br />Sympathetic chain ganglion <br />Can also be called paaravertebral ganglion or lateral ganglion <br />These are found on both sides of the vertebral column <br />Innervates body wall, inside the thoracic cavity, and head and limbs <br /> <br />Collateral ganglia <br />Prevertebral ganglia <br />Innervates tissues and organs in the abdominopelvic cavity <br /> <br /> <br />Adrenal medullae <br />The center of each adrenal gland <br />Neurotransmitters released directly into the blood stream <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Sympathetic chain ganglion <br />Preganglionic fibers that carry motor commands that target structures in the body wall, thoracic cavity, or in the head, neck, or limbs, it will synapse in one or more sympathetic chain ganglion <br />Postganglionic fibers paths will differ <br />Postganglionic fibers <br />These control effectors in the body wall, head, neck, limbs <br /> <br />Organization and anatomy of the sympathetic division <br />The T1 and L2 spinal segments contain sympathetic preganglionic fibers <br />These segments of T1-L2, ventral roots give rise to myelinated white ramus <br />Which then lead to sympathetic chain ganglia or in the adrenal medulla <br />Sympathetic chain ganglia <br />Two final routes <br />Postganglionic fibers which control visceral effectors in wall, head, neck, or limbs <br />Potganglionic fibers which innervate structures of the heart and lungs form sympathetic nerves <br /> <br /> <br />Summary <br />The cervical, inferior lumbar, and sacral chain receive preganglionic innervation by preganglionic fibers from spinal segments T1 – L2 and every spinal nerve receives a gray ramus from a ganglionic of the sympathetic chain <br />Only the thoracic and superior lumbar ganglion T1 – L2 receive preganglionic fibers from white rami <br />Every spibal nerve receives gray ramus from a ganglion of the sympathetic chain <br />Collateral Ganglia <br />Figure 16.5 The Distribution of Sympathetic Innervation <br />Postganglionic fibers <br />Rejoin spinal nerves and reach their destination by way of the dorsal and ventral rami <br />Those targeting structures in the thoracic cavity form sympathetic nerves <br />Go directly to their destination <br />Abdominopelvic viscera <br />Sympathetic innervation via preganglionic fibers synapse within collateral ganglia <br />Splanchic nerves <br />Abdominopelvic viscera <br />Celiac ganglion <br />Innervates stomach, liver, gall bladder, pancreas, spleen <br />Superior mesenteric ganglion <br />Innervates small intestine and initial portion of large intestine <br />Inferior mesenteric ganglion <br />Innervates kidney, urinary bladder, sex organs, and final portion of large intestine <br />Sympathetic activation <br />In crises, the entire sympathetic division responds <br />Sympathetic activation <br />Affects include increased alertness, energy and euphoria, increased cardiovascular and respiratory activities, elevation in muscle tone, mobilization of energy resources <br />Neurotransmitters and sympathetic function <br />Stimulation of sympathetic division has two distinct results <br />Release of ACh or NE at specific locations <br />Secretion of E and NE into general circulation <br />Most postganglionic fibers are adrenergic, a few are cholinergic or nitroxidergic <br />Two types of receptors are alpha receptors and beta receptors <br />Sympathetic ganglionic neurons end in telodendria studded with varicosities filled with neurotransmitter <br />Adrenal Medullae <br />Preganglionic fibers enter an adrenal gland and proceed to its center, which is called adrenal medulla <br />This is a sympathetic ganglion <br />Here hormones are released into the blood stream <br />Secret epinephrine and norepinephrine <br />Blood is the vehicle which carries these chemical messengers <br /> <br />Sympathetic summary of activation <br />Increased alertness <br />Feeling of energy <br />Increased cardiovascular and respiratory activity <br />Elevation of muscle tone <br />Mobilization of energy reserves, breakdown of glycogen in muscle and liver cells and the release of lipids from storage <br />Figure 16.6 Sympathetic Variosities <br />Sympathetic summary division. <br />Two sets of sympathetic chain ganglion <br />Thee collateral ganglion <br />Two adrenal medullae <br />Preganlionic fibers re short <br />Postganglionic fibers are long <br />Typical examples of divergence <br />Single neuron can control many visceral effectors <br />Preganglionic fibers release ACH <br />Post ganglionic fibers release NE <br />Works through secondary messengers <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597484218501440?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974832645715272004-09-23T14:26:00.000-07:002004-09-23T14:27:12.646-07:00Learning Objectives <br />Compare the organization of the autonomic nervous system with the somatic nervous system. <br />Describe the structures and functions of the sympathetic and parasympathetic divisions of the ANS. <br />Describe the mechanisms of neurotransmitter release in the sympathetic and parasympathetic divisions. <br />Describe the effects of sympathetic and parasympathetic neurotransmitters on target organs and tissues. <br />Learning Objectives <br />Describe the hierarchy of interacting levels of control in the ANS <br />Explain how memories are created, stored and recalled. <br />Summarize the effects of aging on the nervous system. <br />SECTION 16-1 An Overview of the ANS <br />General information <br />Neural Integration II: The Autonomic Nervous System and Higher Order Functions <br />There are going to be two major goals here, compare: <br />The neural interactions that direct motor output <br />The subdivisions of the ANS based on structural and functional patters <br /> <br />Common ground <br />Both the somatic and autonomic nervous systems are efferent that carry motor commands to the skeletal system <br />In the somatic nervous system the commands form the CNS exert direct control over the the skeletal muscle <br />In the ANS motor neurons of the CNS synapse on visceral motor neurons in autonomic ganglion and it is through the ganglion that control is exerted <br /> <br />More <br />The visceral motor neurons of the CNS are known as preganglionic neurons and the axons are called prehanglionic fibers <br />Those that leave the ganglion are called postganglionic fibers <br /> <br /> <br />Somatic or visceral information input <br />Input can trigger visceral reflexes and these motor commands are distributed by the ANS <br />ANS (review) <br />Coordinates cardiovascular, respiratory, digestive, urinary and reproductive functions <br />Preganglionic neurons in the CNS send axons to synapse on ganglionic neurons in autonomic ganglia outside the CNS <br />Divisions of the ANS <br />Most often the divisions have opposing effects <br />However, some divisions are only controlled by one of the divisions <br />Sympathetic division (thoracolumbar, "fight or flight") <br />Thoracic and lumbar segments <br />Parasympathetic division (craniosacral, "rest and repose") <br />Preganglionic fibers leaving the brain and sacral segments <br />A general statement <br />The parasympathetic nervous system dominates under resting conditions <br />And the sympathetic nervous system kicks in under times of stress <br /> <br />Eneteric nervous system <br />Generally local control over digestive properties <br />But the activity can also be influenced by both the sympathetic and parasympathetic divisions <br />SECTION 16-2 The Sympathetic Division <br />Sympathetic division anatomy <br />Preganglionic neurons between segments T1 and L2 <br />Ganglionic neurons in ganglia near vertebral column <br />The preganlionic fibers are short and the postganglionic fibers are long <br />The job is to prepare the body for fight of flight responses <br />Specialized neurons in adrenal glands <br />Parasympathetic division <br />The preganlionic fibers originate in the brain stem and the sacral segments of the spinal cord <br />They synapse in ganglion which are close to the target organ <br />This means that the preganlionic fibers are long and the postganglionic fibers are short <br />Job is to conserve energy <br />This means that if you consume a heavy meals, the activity is for digestions, absorption, and waste removal <br />Figure 16.3 The Organization of the Sympathetic Division of the ANS <br />Sympathetic division <br />The division consists of preganglionic neurons that are located between segments T1 and L2 of the spinal cord <br />The cell bodies are located in the gray matter of the lateral gray horns of their axons axons enter the ventral root at three segments <br /> <br />Sympathetic chain ganglion <br />Can also be called paaravertebral ganglion or lateral ganglion <br />These are found on both sides of the vertebral column <br />Innervates body wall, inside the thoracic cavity, and head and limbs <br /> <br />Collateral ganglia <br />Prevertebral ganglia <br />Innervates tissues and organs in the abdominopelvic cavity <br /> <br /> <br />Adrenal medullae <br />The center of each adrenal gland <br />Neurotransmitters released directly into the blood stream <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Figure 16.4 Sympathetic Pathways <br />Sympathetic chain ganglion <br />Preganglionic fibers that carry motor commands that target structures in the body wall, thoracic cavity, or in the head, neck, or limbs, it will synapse in one or more sympathetic chain ganglion <br />Postganglionic fibers paths will differ <br />Postganglionic fibers <br />These control effectors in the body wall, head, neck, limbs <br /> <br />Organization and anatomy of the sympathetic division <br />The T1 and L2 spinal segments contain sympathetic preganglionic fibers <br />These segments of T1-L2, ventral roots give rise to myelinated white ramus <br />Which then lead to sympathetic chain ganglia or in the adrenal medulla <br />Sympathetic chain ganglia <br />Two final routes <br />Postganglionic fibers which control visceral effectors in wall, head, neck, or limbs <br />Potganglionic fibers which innervate structures of the heart and lungs form sympathetic nerves <br /> <br /> <br />Summary <br />The cervical, inferior lumbar, and sacral chain receive preganglionic innervation by preganglionic fibers from spinal segments T1 – L2 and every spinal nerve receives a gray ramus from a ganglionic of the sympathetic chain <br />Only the thoracic and superior lumbar ganglion T1 – L2 receive preganglionic fibers from white rami <br />Every spibal nerve receives gray ramus from a ganglion of the sympathetic chain <br />Collateral Ganglia <br />Figure 16.5 The Distribution of Sympathetic Innervation <br />Postganglionic fibers <br />Rejoin spinal nerves and reach their destination by way of the dorsal and ventral rami <br />Those targeting structures in the thoracic cavity form sympathetic nerves <br />Go directly to their destination <br />Abdominopelvic viscera <br />Sympathetic innervation via preganglionic fibers synapse within collateral ganglia <br />Splanchic nerves <br />Abdominopelvic viscera <br />Celiac ganglion <br />Innervates stomach, liver, gall bladder, pancreas, spleen <br />Superior mesenteric ganglion <br />Innervates small intestine and initial portion of large intestine <br />Inferior mesenteric ganglion <br />Innervates kidney, urinary bladder, sex organs, and final portion of large intestine <br />Sympathetic activation <br />In crises, the entire sympathetic division responds <br />Sympathetic activation <br />Affects include increased alertness, energy and euphoria, increased cardiovascular and respiratory activities, elevation in muscle tone, mobilization of energy resources <br />Neurotransmitters and sympathetic function <br />Stimulation of sympathetic division has two distinct results <br />Release of ACh or NE at specific locations <br />Secretion of E and NE into general circulation <br />Most postganglionic fibers are adrenergic, a few are cholinergic or nitroxidergic <br />Two types of receptors are alpha receptors and beta receptors <br />Sympathetic ganglionic neurons end in telodendria studded with varicosities filled with neurotransmitter <br />Adrenal Medullae <br />Preganglionic fibers enter an adrenal gland and proceed to its center, which is called adrenal medulla <br />This is a sympathetic ganglion <br />Here hormones are released into the blood stream <br />Secret epinephrine and norepinephrine <br />Blood is the vehicle which carries these chemical messengers <br /> <br />Sympathetic summary of activation <br />Increased alertness <br />Feeling of energy <br />Increased cardiovascular and respiratory activity <br />Elevation of muscle tone <br />Mobilization of energy reserves, breakdown of glycogen in muscle and liver cells and the release of lipids from storage <br />Figure 16.6 Sympathetic Variosities <br />Sympathetic summary division. <br />Two sets of sympathetic chain ganglion <br />Thee collateral ganglion <br />Two adrenal medullae <br />Preganlionic fibers re short <br />Postganglionic fibers are long <br />Typical examples of divergence <br />Single neuron can control many visceral effectors <br />Preganglionic fibers release ACH <br />Post ganglionic fibers release NE <br />Works through secondary messengers <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597483264571527?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974507752205782004-09-23T14:16:00.000-07:002004-09-23T14:21:47.753-07:00Chapter 15, part 2 <br />Neural Integration I: Sensory Pathways and the Somatic Nervous System <br />SECTION 15-3 The Organization of Sensory Pathways <br />First, second, and third order neurons <br />First order neurons <br />Sensory neurons that deliver sensory information to the CNS <br />Second order neurons <br />First order neurons synapse on these in the brain or spinal cord <br />Third order neurons <br />Found in the thalamus <br />Second order neurons synapse on these <br />First order neuron <br />Delivers sensations to the CNS <br />The cell body is found in the dorsal root ganglion or the cranial root ganglion <br />Second order neuron <br />Often found in the spinal cord or the brain stem <br />If the sensation is to reach our CNS, then the information must be posted to a third order neuron <br />Third order neuron <br />Found in the thalamus <br />These synapse on sensory areas of the primary sensory cortex <br /> <br />Somatic sensory pathways: divisions <br />Three major pathways carry sensory information <br />Posterior column pathway <br />Anterolateral pathway <br />Spinocerebellar pathway <br />Figure 15.6 Sensory Pathways and Ascending Tracts in the Spinal Cord <br />Posterior column pathway <br />Carries fine touch, pressure and proprioceptive sensations <br />Axons ascend within the fasciculus gracilis and fasciculus cuneatus <br />Relay information to the thalamus via the medial lemniscus <br />Decussation occurs <br />How do we locate? <br />Our ability to determine where something is happening depends on the projection of information to the thalamus to the primary sensory cortex <br />Sensory information for head and toe arrive at different locations <br />Without this you could determine light touch but not location <br />The number of receptors is not determined by the size of the area, the face has more sensory response then the back <br />The tongue has many more receptors then the back <br />Figure 15.8 The Posterior Column Pathway and the Spinothalamic Tracts <br />Anteriorlateral pathways <br />Conscious sensations of poorly located touch, pressure, pain, and temperature <br />First order neurons enter the spinal cord synapse on second order neurons in the posterior gray horn <br />These axons cross to the opposite side of the spinal cord before ascending <br />This pathway delivers sensations to the reflex centers of the brain stem and then on to the cerebral cortex <br />The anterior spinothalamic tracts carry crude touch and pressure <br />The lateral spinothalamic tracts carry pain and temperature <br />Both of these end on third order neurons in the thalamus <br />Them relayed to primary sensory cortex regions <br />Figure 15.8 The Posterior Column Pathway and the Spinothalamic Tracts <br />Spinocerebellar pathway <br />Includes the posterior and anterior spinocerebellar tracts <br />Carries sensation to the cerebellum concerning position of muscles, tendons and joints to the cerebellum <br />Information does not reach conscious awareness <br />Axons of first order neurons synapse on interneurons of the gray horns <br />These second order neurons ascend in two tracts: posterior spinocerebellar and anterior spinocerebellar <br />Figure 15.9 The Spinocerebellar Pathway <br />Visceral sensory pathways <br />Carry information collected by interoceptors <br />Most of the information collected from cranial nerves V, VII, IX and X delivered to solitary nucleus in medulla oblongata <br />Dorsal roots of spinal nerves T1 – L2 carry visceral sensory information from organs between the diaphragm and pelvis <br />Dorsal roots of spinal nerves S2 – S4 carry sensory information below this area <br />Most information never reaches the primary sensory cortex so we generally remain unaware of these sensations <br /> <br />What kind of receptors are there? <br />Nociceptors <br />Thermorecptors <br />Tactile receptors <br />Baroreceptors <br />chemoreceptors <br />SECTION 15-4 The Somatic Nervous System <br />Objectives <br />Describe the components, processes, and functions of the somatic pathways <br />Describe the levels of information processing involved in motor control <br />Somatic Motor pathways General <br />Motor commands issued by the CNS are distributed by the somatic nervous system and the autonomic nervous system <br />The SAS controls the contractions of skeletal muscle and is under voluntary control <br />The ANS is responsible for visceral control, or involuntary control <br />Somatic motor pathways <br />Upper motor neuron <br />Cell body lies in a CNS processing center <br />Lower motor neuron <br />Cell body located in a motor nucleus of the brain or spinal cord <br />Figure 15.10 Descending (Motor) Tracts in the Spinal Cord <br />The corticospinal pathway <br />Also called the pyramidal system <br />Provides voluntary skeletal muscle control <br />This is a direct pathway upper on lower neurons <br />Also can be indirect by innervating medial and lateral pathways <br />Corticobulbar tracts terminate at cranial nerve nuclei <br />Corticospinal tracts synapse on lower motor neurons in the anterior gray horns of the spinal cord <br />Visible along medulla as pyramids <br />The three cortisospinal tracts <br />Corticobullar <br />Lateral cortiospinal <br />Anterior corticospinal <br /> <br />Corticobullar tracts <br />Synapses on lower motor neurons <br />III, IV, VI, VII, IX, XI, and XII <br />Provide conscious control over skeletal muscle that move the eye, face, jaw, neck, and pharynx <br /> <br />Corticospinal tracts <br />Synapse on lower motor neurons in gray horn of spinal cord <br />These are visible as thick bands of neurons called the pyramids <br />These tracts then cross over to the other side to enter the descending lateral corticospinal on the opposite side of the cord <br />The rest continue on the same side of anterior corticospinal tracts <br />Pyramids (review) <br />Most of the axons decussate to enter the descending lateral corticospinal tracts <br />Those that do not cross over enter the anterior corticospinal tracts <br />Provide rapid direct method for controlling skeletal muscle <br />Figure 15.11 The Corticospinal Pathway <br />The Motor homunculus <br />This is the map region of motor activities <br />The proportions of motor homunculus are different then the parts of the body they effect <br />The area is proportional to the number of motor units present in that area <br />The finer the motor control, the more motor units affected, therefore that area has a larger motor homunculus <br />The medial and lateral pathways <br />Several centers in the cerebrum, diencephalon, and brain stem issue somatic motor commands as the result of processing at the subconscious level <br />These are known as being extrapyramidal system (ESP) <br />They are better described as being: <br />The medial and lateral pathways <br />Issue motor commands as a result of subconscious processing <br />They can modify or direct muscle contractions by stimulating, facilitating or inhibiting lower motor neurons <br />What are these connections like? <br />Axons of the upper motor neurons in the lateral and medial pathways synapse on the same lower motor neurons innervated by the corticospinal pathway <br />This means that there is dual motor control, primary motor cortex and brain stem but also at the level of the lower motor neuron <br />Medial pathway <br />Its job is the primar control of gross movements of the trunk and proximal limbs <br />The upper motor neurons are located in the: <br />Receive information over the vestibular-cochlear nerve (VIII) from receptors in the inner ear that monitor position and movement of the head <br />Primary goal is to maintain posture and balance <br />The descending fibers in the spinal cord constitute the vestibulospinal tracts <br /> <br />Tectospinal tracts <br />These arise out of the colliculi <br />These receive sensory information <br />Motor axons here descend through this tract <br />They cross over before they synapse on the lower motor neurons <br /> <br />Reticulospinal tracts <br />This is a loose network which extend throughout the brain stem <br />Receives input from all ascending and descending pathways <br />It has extensive connections with the cerebrum, cerebellum and the brain stem <br />The axons of the upper motor neurons of the reticular formation descend through this pathway <br />Different areas control different areas also <br />lateral pathways <br />Lateral pathway <br />Controls muscle tone and movements of the distal muscles of the upper limbs but not as significant as those of the lateral corticospinal tracts <br />Important in maintaining motor control and muscle tone in upper limbs if the corticospinal pathways are damaged <br />They upper motor neurons lie within the red nuclei of the mesencephalon <br />This neurons cross over to the other side and descent through the rubrospinal tracts and extend only to the cervical spinal cord <br />Job of the baal nuclei and the cerebellum <br />The coordination and feedback control over muscle contractions for both conscious and subconscious activity <br />The basal nuclei <br />Responsible for the background pattern movements <br />This is especially true of rhythmic cyclic patterns movement for walking and running <br />They adjust the activity of the upper motor neurons based on the information provided by the cerebral cortex and the substantia nigra <br /> <br />Two basic nuclei exist <br />One group synapse on the thalamic neurons which send their axons to the premotor cortex association center that will direct the activity of the primary motor cortex <br />This controls the information passed on the corticospinal tract <br />The second group <br />Synapse on the reticular formation altering inhibitory or excitatory activity of the reticulospinal tract <br /> <br />What are the types of neurons that exist? <br />One the stimulates neurons by releasing Ach <br />The other inhibits neurons by releasing gamma amino butyric acid <br /> <br />Injury? <br />The primary motor cortex is responsible for fine motor control over skeletal muscles <br />Some voluntary movements can be controlled by the basal nuclei, only the movements are not as precise <br />The cerebellum <br />The cerebellum monitors proprioceptive, visual, vestibular sensory information <br />Axons relaying proprioceptive information reach the cerebellar cortex in the spinocebellar tracts <br />Visual is relayed from the superior colliculi <br />Balance information is relayed from the vestibullar nuclei <br />The net result is affecting the upper motor neuron activity of the corticospinal, medial and lateral pathways <br />More <br />All motor pathways send information to the cerebellum where the motor commands are issued <br />Movement then proceeds and is monitored by the cerebellum <br />The cerebellum adjusts movements based upon proprioceptive and vestibular information received <br />It is the job of the cerebellum to refine the cerebellar decision to move with the appropriate number of muscle units <br />The basal nuclei and cerebellum in review <br />Basal nuclei adjust motor commands issued in other processing centers <br />Provide background patterns of movement involved in voluntary motor movements <br />Cerebellum monitors proprioceptive information, visual information and vestibular sensations <br />Levels of processing and motor control activity <br />Always remember that these are a series of pathways involving synapses <br />Many activities are performed without you thinking about doing them <br />This is all a process may not involve evaluation by the cerebral cortex <br />Basic functions in the medulla and become more complex in the cerebral cortex at the primary motor center <br />control and responses <br />Levels of processing and motor control <br />Spinal and cranial reflexes provide rapid, involuntary, preprogrammed responses are the first to appear and are directed by the brain stem and mesencephalon in infants <br />Voluntary responses, learned behaviors are <br />More complex appear later and require more time to prepare and execute <br />Figure 15.12 Centers of Somatic Motor Control <br />During development( review) <br />Spinal and cranial reflexes are first to appear in infants <br />Complex reflexes develop as CNS matures and brain grows and more connections are made <br />More connections are made until age four <br />The pathways that develop will have long term affects on metal capabilities <br />You should now be familiar with: <br />The components of the afferent and efferent divisions of the nervous system, and what is meant by the somatic nervous system. <br />Why receptors respond to specific stimuli and how the organization of a receptor affects its sensitivity. <br />The major sensory pathways. <br />How we can distinguish among sensations that originate in different areas of the body. <br />The components, processes and functions of the somatic motor pathways. <br />The levels <br />of information processing involved in motor control. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597450775220578?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095974145119615222004-09-23T14:15:00.000-07:002004-09-23T14:15:45.120-07:00Chapter 15, part 1 <br />Neural Integration I: Sensory Pathways and the Somatic Nervous System <br />Learning Objectives <br />Specify the components of the afferent and efferent divisions of the nervous system, and explain what is meant by the somatic nervous system. <br />Explain why receptors respond to specific stimuli and how the organization of a receptor affects its sensitivity. <br />Identify the major sensory pathways. <br />Learning Objectives <br />Explain how we can distinguish among sensations that originate in different areas of the body. <br />Describe the components, processes and functions of the somatic motor pathways. <br />Describe the levels of information processing involved in motor control. <br />SECTION 15-1 An Overview of Sensory Pathways and the Somatic Nervous System <br />Special senses <br />These are much more complex receptors then those of the general sense <br />The receptors are located in sense organs <br />This information is then distributed to specific regions of the cerebral cortex <br />Auditory <br />Visual <br />Etc <br /> <br />Specialized receptors <br />In these cases the receptor potential and the generator potential occur in different cells of the sensory neuron <br />Specialized receptors <br />Taste <br />Hearing <br />Equilibrium <br />Vision <br /> <br />Neural pathways <br />Afferent pathways <br />Sensory information coming from the sensory receptors through peripheral nerves to the spinal cord and on to the brain <br />Efferent pathways <br />Motor commands coming from the brain and spinal cord, through peripheral nerves to effecter organs <br />Figure 15.1 An Overview of Neural Integration <br />SECTION 15-2 Sensory Receptors and their Classification <br />What are Receptors <br />These are specialized cells or cell processes which provide your central nervous system with information about conditions inside and outside of the body <br />There is a term called general senses which is used to describe our sensitivity to: <br />Temperature <br />Pain <br />Touch <br />Vibration <br />Pressure <br />Proprioception <br />Sensory Receptors <br />The goal of a sensory receptor is to collect information and detail it in an action potential for transduction to the central nervous system <br />This is a graded response, the stronger the potential, the stronger the signal sent to the CNS <br />However, the receptor potential must be strong enough to generate a action potential <br /> <br />The detection of stimuli <br />The key here is that the receptors are specific for their job <br />This is a form of division of labor <br />A touch receptor would not respond strongly to a chemical stimuli <br />This is called receptor specificity <br />The area which is monitored is called the receptive field <br /> <br />What is the receptive field? <br />Some areas have many receptors and therefore the field is monitored better <br />If there are fewer receptors, the monitoring is poorer <br />Regardless of the receptor, information must be sent to the CNS <br /> <br />Sensory receptor <br />Specialized cell or cell process that monitors specific conditions <br />Arriving information is a sensation <br />Awareness of a sensation is a perception <br />How is specificity determined? <br />It is the structure of the receptor and its associated structures which determine how the receptor responds <br />Senses <br />General senses <br />Pain <br />Temperature <br />Physical distortion <br />Chemical detection <br />Receptors for general senses scattered throughout the body <br />Special senses <br />Located in specific sense organs <br />Structurally complex <br />Sensory receptors <br />Each receptor cell monitors a specific receptive field <br />Transduction <br />A large enough stimulus changes the receptor potential, reaching generator potential <br />The interpretation of sensory information <br />Sensory information that arrives at the CNS is routed to the appropriate location depending on the source <br />Those of touch reach the region called the primary sensory cortex <br />Those of visual, auditory, gustatory, and olfaction reach appropriate areas of the cortex <br />Receptors <br />Tonic receptors <br />Always active <br />Slow acting receptors <br />Phasic receptors <br />Provide information about the intensity and rate of change of a stimulus <br />Fast acting receptors <br />Adaptation <br />Is defined as the reduction in sensitivity in the presence of a constant stimulus <br /> <br />Fast adapting receptors <br />Thermoreceptors <br />temperature <br />Slow adapting receptors <br />Noiceptors <br />Pain <br /> <br />Central adaptation <br />This occurs from the CNS <br />Conscious awareness of the stimuli disappears <br /> <br />Peripheral adaptation <br />This reduces the amount of information which reaches the CNS <br />Information is processed at the spinal cord or brain stem and might not reach the higher centers of the brain <br />These often produce reflex motor responses that we are not aware of <br /> <br />Higher centers of control sensitivity <br />Output from higher centers can increase or decrease receptor sensitivity or facilitate transmission along a sensory pathway <br />Often involves the mesencephalon and the reticular activating system <br /> <br />General receptor classification <br />Exteroceptors: external environment <br />Proprioceptors: skeletal muscle and joints related to position <br />Interoceptors: monitors visceral organ functions <br /> <br />Detailed Classification of sensory receptors <br />Noiceptors: pain <br />Thermoreceptors: temperature <br />Mechanoreceptors: physical distortion <br />Chemorecpetors: chemical concentration <br /> <br />Differences <br />EACH receptor is unique in design <br />The difference between a somatic and a visceral receptor is location, location, location <br />A pain receptor in the gut looks like a pain receptor on the surface of the skin <br />However, the two send their information to different location <br />Proprioception is purely somatic <br />The visceral organs have fewer pain, temperature, and touch receptors <br />Only about 1 percent of the information that reaches the spinal cord or the brain stem actually reaches the CNS <br />The general senses <br />Three types of nociceptor <br />Provide information on pain as related to extremes of temperature <br />Provide information on pain as related to extremes of mechanical damage <br />Provide information on pain as related to extremes of dissolved chemicals <br />Myelinated type A fibers carry fast pain <br />Slower type C fibers carry slow pain <br />Theromreceptors <br />Free nerve endings of the dermis, skeletal muscle, liver, and hypothalamus <br />Cold receptors more common then hot <br />No structural difference <br />They are phasic receptors which send their information to the reticular formation, thalamus, and the primary sensory cortex <br /> <br />Mechanoreceptors <br />They respond when their cell membranes are distorted <br />They are often described as being mechanically regulated <br />They fall into three classes: <br />Tactile responses <br />Baroreceptors <br />Proprioceptors <br /> <br />Tactile receptors <br />Provide information for: <br />Touch: shape and texture <br />Pressure: mechanical distortion <br />Vibration: pulsating sounds <br />Touch vs pressure understanding depends on the degree of stimulation <br />Figure 15.2 Receptors and Receptive Fields <br />Thermoceptors and mechaniceptors (review) <br />Found in the dermis <br />Mechaniceptors <br />Sensitive to distortion of their membrane <br />Tactile receptors (six types) <br />Baroreceptors <br />Proprioceptors (three groups) <br />Figure 15.3 Tactile Receptors in the Skin <br />Tactile receptors of the skin <br />Fine touch and pressure receptors can provide information about the source of stimulation which can include location, size, shape, texture, and movement because of the narrow receptor fields <br />Crude touch and pressure provide poor localization because of the large receptor fields <br />Types: <br />Free nerve endings: <br />Root hair plexus: <br />Tactile discs: <br />Lamellated discs <br />Ruffini corpuscles <br />Free nerve endings <br />Sensitive to touch and pressure <br />Described as being tonic with narrow receptor fields <br />Root hair plexus <br />Monitor distortions and movements across the body <br />Sensory dendrites are stimulated and produce action potentials <br />Adapt rapidly with a narrow receptor field <br />Tactile discs <br />Required for fine touch and pressure receptors <br />Sensitive with very small receptor fields <br />Tactile Corpuscles <br />Perceive sensation of fine touch and pressure and low frequency vibration <br />Typically found in very sensitive areas of the skin <br />Lamellated corpuscles <br />Sensitive to deep pressure <br />Adapt rapidly <br />Ruffini corpuscles <br />Sensitive to pressure and distortion of the skin <br />Tonic receptors without adaption <br />Baroreceptors <br />Required for the monitoring of pressure <br />Consists of free nerve endings found in the wall of an an organ or on the elastic walls of a blood vessel <br />When there is a change in the elastic walls of a blood vessel an action potential is sent <br />They are highly adaptive <br />Major role in the monitoring of cardiac output. Adjust bllood pressure, and lung expansion <br />There are also stretch receptors in the GI tract as well <br /> <br />Proprioceptors <br />Monitors the position of joints, tendons, and ligaments and the state of muscle contraction <br />Muscle spindles <br />Golgi tendon organs <br />Receptors in joint capsules <br /> <br />Muscle spindles <br />Monitors skeletal muscle length <br />Golgi tendon organs <br />Location between the skeletal muscle and a tendon <br />Stimulated by tension in the tendon <br />Monitors external tension of a muscle <br />Goal is to prevent tearing <br />Receptors in joint capsules <br />Detect pressure, tension, and movement at the joint <br />Helps regulates your sense of body position with the inner ear <br /> <br />What is the job of chemoreceptors? <br />They are specialized neurons which can detect small changes in the concentration of specific chemicals or compounds <br />In general response only to those chemicals which are water soluble <br />Demonstrate peripheral adaptation and then central adaptation <br />What they do not do? <br />They do not send information to the primary sensory cortex <br />Information is sent to the brain stem which can then alter the respiratory and cardiovascular activities <br /> <br />What do they respond to? <br />Neurons of the respiratory center of the brain respond to the concentration of hydrogen ions in the blood, that is the blood pH and the carbon dioxide molecule in the CSF <br />Chemoreceptors <br />Chemoreceptors: location <br />Carotid bodies: internal carotid artery <br />Aortic bodies: aortic arch <br />Information from here is passed to cranial nerves IX (glossopharyngeal) and X (vagus) <br />Figure 15.4 Baroreceptors and the Regulation of Visceral Function <br />Figure 15.5 Chemoreceptors <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109597414511961522?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095456138266307242004-09-17T14:22:00.000-07:002004-09-17T14:22:18.266-07:00Chapter 14, part 4 <br />The Brain and Cranial Nerves <br />Olfactory nerves (I) <br />Carry sensory information responsible for the sense of smell <br />Synapse within the olfactory bulb <br />Figure 14.21 The Olfactory Nerve <br />cranial nerves II, III, IV <br />Optic nerves (II) <br />Carry visual information from special sensory receptors in the eyes <br />Occulomotor nerves (III) <br />Primary source of innervation for 4 of the extraocular muscles <br />Trochlear nerves (IV) <br />Innervate the superior oblique muscles <br />Figure 14.23 Cranial Nerves Controlling the Extra-ocular Muscles <br />cranial nerves V, VI, VII <br />Trigeminal nerves (V) <br />Missed nerves with ophthalmic, maxillary and mandibular branches <br />Abducens nerve (VI) <br />Innervates the lateral rectus muscles <br />Facial nerves (VII) <br />Mixed nerves that control muscles of the face and scalp <br />Provide pressure sensations over the face <br />Receive taste information from the tongue <br />Figure 14.24 The Trigeminal Nerve <br />Figure 14.25 The Facial Nerve <br />cranial nerves VIII, IX <br />Vestibulocochlear nerves (VIII) <br />Vestibular branch monitors balance, position and movement <br />Cochlear branch monitors hearing <br />Glossopharyngeal nerves (IX) <br />Mixed nerves that innervate the tongue and pharynx <br />Control the action of swallowing <br />cranial nerves X <br />Vagus nerves (X) <br />Mixed nerves <br />Vital to the autonomic control of visceral function <br />Figure 14.26 The Vestibulocochlear Nerve <br />Figure 14.27 The Glossopharyngeal Nerve <br />Figure 14.28 The Vagus Nerve <br />cranial nerves XI, XII <br />Accessory nerves (XI) <br />Internal branches <br />Innervate voluntary swallowing muscles of the soft palate and pharynx <br />External branches <br />Control muscles associates with the pectoral girdle <br />Hypoglossal nerves (XII) <br />Provide voluntary motor control over tongue movement <br />Figure 14.29 The Accessory and Hypoglossal Nerve <br />SECTION 14-10Cranial Reflexes <br />Cranial reflexes <br />Involve sensory and motor fibers of cranial nerves <br />You should now be familiar with: <br />The major regions of the brain and their functions. <br />The formation, circulation and functions of the CSF. <br />The main components of the medulla oblongata, the pons, the cerebellum, the mesencephalon, the diencephalon, and the limbic system and their functions. <br />The major anatomical subdivisions of the cerebrum. <br />The motor, sensory and association areas of the cerebral cortex. <br />Representative examples of cranial reflexes. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109545613826630724?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095455951213586002004-09-17T14:15:00.000-07:002004-09-17T14:19:11.213-07:00Chapter 14, part 3 <br />The Brain and Cranial Nerves <br />SECTION 14-8The Limbic System <br />General description <br />It includes nuclei and tracts along the border of the cerebrum and the diencephalon <br />This is described as a functional grouping but not a anatomical grouping <br />The functions include: <br />Establishing the emotional state <br />Links the conscious intellectual functions with the conscious and subconscious autonomic functions of the brain stem <br />Facilitating memory storage and retrieval <br />This is a system which is designed to want you to do <br />The limbic system or motivational system includes <br />Amygdaloid body <br />Cingulated gyrus <br />Parahippocampal gyrus <br />Hippocampus <br />Fornix <br />Functions of the limbic system involved emotions and behavioral drives <br />Amygaloid body <br />Appears to be an interface between the limbic system, cerebrum, and sensory neurons <br />Plays a role in the regulation of the heart beat in the fight of flight response <br /> <br />Limbic lobe <br />Consists of gyri which which are underneath the corpus callosum <br /> <br />Three gyri are present <br />Cingulate gyrus <br />Dentate gyrus <br />Parahippocampus gtrus <br /> <br />Cingulate gyri <br />Located superior to the corpus callosum <br /> <br />Dentate gyrus <br />Posterior and inferior portions of the limbic lobe <br /> <br />Parahippocampal gyrus <br />Also posterior and inferior to the limbic lobe <br />Fornix <br />Tract of white matter which connects the white matter of the hippocampus with the hypothalamus <br />Curves medially and ends at the mamillary body <br /> <br />Figure 14.13 The Limbic System <br />Figure 14.14 The Brain in Section <br />Figure 14.14 The Brain in Section <br />SECTION 14-9The Cerebrum <br />Cerebrum: General <br />It is the largest region of the brain <br />Responsible for thoughts and intellectual functions <br />Largely involved in the processing of somatic and sensory information <br />Cerebral cortex: general <br />The two hemispheres are separated by a deep longitudinal fissure <br />The hemispheres are connected by white matter called the corpus callosum <br />Each hemisphere can also be divided into lobes or regions named after the overlying bone component of the skull <br /> <br />Cerebral cortex: general more <br />Each hemisphere is divided into and anterior( frontal) and posterior( parietal) <br />section by the central sulcus <br />The horizontal sulcus separates the frontal lobe from the temporal lobe <br />The cerebral cortex <br />The surface contains gyri and sulci or fissures <br />Longitudinal fissure separates two cerebral hemispheres <br />Central sulcus separates frontal and parietal lobes <br />Temporal and occipital lobes also bounded by sulky <br />Three key points of the cerebral lobes <br />Each hemisphere receives sensory information from and sends motor commands to the opposite of the body <br />The two hemispheres have different functions <br />The assignment of specific function to the brain is imprecise <br />White matter of the cerebrum: review <br />Contains association fibers <br />Commissural fibers <br />Projection fibers <br />Association fibers <br />These connect areas of the neural cortex within a single hemisphere: two types <br />Shorter association fibers are called arcuate fibers <br />The longer fibers are called longitudinal fibers which connect the frontal lobe to the other lobes of the same hemisphere <br />Commissural fibers <br />These interconnect the two hemispheres and allow for cross communication: two types <br />Corpus callosum: <br />These link the two hemisphere together <br />Anterior commissure: <br />Link the hemispheres together <br />Projection fibers <br />Link the cerebral cortex to the diencephalon, brain stem, cerebellum, and the spinal cord <br />All projection fibers must pass through the diencephalon <br />This allows sensory communication to the motor areas which then through descending tracts pass on the appropriate information <br />Figure 14.15 The White Matter of the Cerebrum <br />Basal nuclei: general information <br />This is the other center of the brain outside of conscious levels <br />These are directed by the basal nuclei <br />Gray matter within each hemisphere deep to the floor of the ventricle <br />More <br />They are gray matter found within white matter <br />Projection and commissural fibers travel around them nuclei <br /> <br /> <br />The basal nuclei <br />Caudate nucleus <br />Globus pallidus <br />Putamen <br />Control muscle tone and coordinate learned movement patterns <br />Functions of the basal nuclei <br />Subconscious control of muscle tone and coordination of learned movement <br />They do not initiate a movement, but is responsible for that movement to follow a pattern once that movement has begun <br /> <br />The pattern of movement <br />First information must arrive here from the sensory areas of the cerebral cortex <br />Processing occurs here <br />Output from here goes to the thalamus <br />Information form here go back to the appropriate areas of the cerebral cortex (motor) <br />Then the cerebral cortex issues the motor commands <br />Motor and sensory areas of the cortex <br />Primary motor cortex of the precentral gyrus directs voluntary movements <br />Primary sensory cortex of the postcentral gyrus receives somatic sensory information <br />Touch <br />Pressure <br />Pain <br />Taste <br />Temperature <br />Figure 14.17 The Cerebral Hemispheres <br />Association areas <br />Control our ability to understand sensory information and coordinate a response <br />Somatic sensory association area <br />Visual association area <br />Somatic motor association area <br />general interpretive and speech areas <br />General interpretive area <br />Receives information from all sensory areas <br />Present only in left hemisphere <br />Speech center <br />Regulates patterns of breathing and vocalization <br />cortex functions and hemispheric differences <br />Prefrontal cortex <br />Coordinates information from secondary and special association areas <br />Performs abstract intellectual functions <br />Hemispheric differences <br />Left hemisphere typically contains general interpretive and speech centers and is responsible for language based skills <br />Right hemisphere is typically responsible for spatial relationships and analyses <br />Figure 14.18 Hemispheric Lateralization <br />Electroencephalogram (EEG) <br />Measures brain activity <br />Alpha waves = healthy resting adult <br />Beta waves = concentrating adult <br />Theta waves = normal children <br />Delta waves = normal during sleep <br />Figure 14.19 Brain Waves <br />Focus: Cranial Nerves <br />12 pairs of cranial nerves <br />Each attaches to the ventrolateral surface of the brainstem near the associated sensory or motor nuclei <br />Figure 14.20 Origins of the Cranial Nerves <br />Figure 14.20 Origins of the Cranial Nerves <br />Figure 14.20 Origins of the Cranial Nerves <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109545595121358600?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095289643694930532004-09-15T16:01:00.000-07:002004-09-15T16:07:23.693-07:00Chapter 14, part 2 <br />The Brain and Cranial Nerves <br />SECTION 14-3 The Medulla Oblongata <br />Medulla oblongata <br />It is designed to connect the brain and the spinal cord <br />Contains relay stations and reflex centers <br />Olivary nuclei <br />Cardiovascular and respiratory rhythmicity centers <br />Reticular formation begins in the medulla oblongata and extends into more superior portions of the brainstem <br />General description <br />Inferior portion of the medulla oblangota resembles that of the spinal cord with a small central canal <br />When ascending the medulla toward the brain the central canal opens into the 4th ventricle <br /> <br />Activity <br />All activity between the brain and the spinal cord involve ascending and descending tracts <br />Center for the coordination of many complex visceral and autonomic functions <br /> <br />Autonomic nuclei controlling visceral activities <br />Organized into the reticular formation centers <br />Responsible for the following <br />Reflex centers <br />Cardiovascular centers <br />Cardiac centers <br />Vasomotor centers <br />Respiratory centers <br /> <br />Sensory and Cranial nerves <br />VIII, IX, X, XI, XII <br />Motor commands to the pharnyx, neck, back <br />Commands to the visceral organs <br />VIII provides auditory information <br /> <br />Relay Stations <br />Nucleus gracilis and nucleus cuneatus pass information to the thalamus <br />Solitary nucleus receives visceral information that is passed to the CNS <br />Olivary nuclei pass information to cerebellar cortex <br />Figure 14.7 The Diencephalon and Brain Stem <br />Figure 14.7 The Diencephalon and Brain Stem <br />Figure 14.8 The Medulla Oblongata and Pons <br />Figure 14.8 The Medulla Oblongata and Pons <br />SECTION 14-4 The Pons <br />The pons contains <br />Links the cerebellum with the mesencephalon, diencephalon, cerebrum, and spinal cord <br />Contains sensory and motor nuclei for four cranial nerves <br />Nuclei that help control respiration <br />Nuclei and tracts linking the cerebellum with the brain stem, cerebrum and spinal cord <br />Ascending, descending and transverse tracts <br />Sensory and Motor nuclei of cranial nerves <br />V, VI, VII, VIII <br />Innervate the jaw, anterior surface of the face, lateral rectus muscle, sense organs of the inner ear <br /> <br />Nuclei and control of respiration <br />Each side of the pons have respiratory centers <br />Apneustic and pneumotaxic <br />Modify activity of mendulla oblongata <br /> <br />Nuclei that process information ascending and descending from the Cerebellum <br />Links the cerebellum with the brain stem, cerebrum, and spinal cord <br /> <br />Ascending, descending, and transverse tracts <br />Connects the pons with the cerebellar hemisphere of the opposite side <br /> <br />Figure 14.8 The Medulla Oblongata and Pons <br />Figure 14.8 The Medulla Oblongata and Pons <br />SECTION 14-5 The Cerebellum <br />What is it? <br />It is an automatic processing center with two functions <br />Adjusting the postural muscle of the back <br />Programming and fine tuning movements controlled at both the conscious and subconscious levels <br />Adjusting postural muscles of the body <br />Coordinates rapid, automatic adjustments that maintain balance and equilibrium <br />Means alterations in muscle tone <br />Programming <br />Refines learned movement patterns <br />The cerebellum compares the motor commands with sensory information and adjusts to make movements smooth <br />The cerebellum <br />Adjusts postural muscles and tunes on-going movements <br />Cerebellar hemispheres <br />Anterior and posterior lobes are separated by a primary fissure <br />Vermis: midline band of cortex tissue <br />Flocculonodular lobe: lines between roof of the fourth ventricle, cerebellar hemispheres, and verrmis <br />More on construction <br />Cerebellum has a superficial layer of neural cortex <br />Many Purkinje fibers are present which create a tree like appearance called the arbor vitae <br />More on construction <br />Superior, middle and inferior cerebellar peduncles link cerebellum with brain stem, diencephalon, cerebrum, and spinal cord <br />Superior cerebellar peduncles <br />Link the cerebellum with the midbrain, diencephalon, and the cerebrum <br /> <br /> <br />Middle cerebellar penduncles <br />Connect the cerebellar hemispheres with sensory and motor nuclei in the pons <br /> <br />Inferior cerebellar penduncles <br />Links the cerebellum to the medulla oblangota and the spinal cord <br />Figure 14.9 The Cerebellum <br />Figure 14.9 The Cerebellum <br />SECTION 14-6The Mesencephalon <br />Figure 14.10 The Mesencephalon <br />The composition of the Mesencephalon <br />Tectum <br />Walls and floor <br />White matter <br />Tectum <br />Gray matter <br />Superior colliculi <br />Integrate visual information with sensory outputs and initiates reflex responses to visual stimuli <br />Inferior collicul <br />Gray matter <br />Relays auditory information to medial geniculate, initiates reflex response to auditory stimuli <br /> <br />Walls and floor <br />All gray matter <br />Red nuclei <br />Subconscious control of upper limb position and back muscle tone <br />Substantia nigra <br />Regulates basal nuclei <br />Recicular formation <br />Automatic processing of incoming sensations and outgoing motor commands <br />Help maintain conscious <br /> <br />White matter <br />Cerebral peduncles <br />Connects primary motor cortex with motor neurons in brain, and spinal cord <br />Carries sensory information on ascending tracts to the thalamus <br />The mesencephalon: review <br />The tectum (roof) contains the corpora quadrigemina <br />Superior and inferior colliculi <br />The mesencephalon contains many nuclei <br />Red nucleus <br />Substantia nigra <br />Cerebral peduncles <br />RAS headquarters <br />SECTION 14-7The Diencephalon <br />General information <br />Important role in the integration of conscious and subconscious activities for both sensory and motor commands <br />The diencephalon: divisions <br />Epithalamus: roof of the diencephalon <br />Posterior portion contains then pineal gland <br />melatonin <br />Thalamus <br />Hypothalamus <br />The thalamus <br />Final relay point for ascending sensory information that will be projected to the primary sensory cortex <br />Acts as a filter to pass on information <br />Coordinates the activities of the cerebral cortex and basal nuclei by relaying information between them <br />The left and the right thalamus are separated by the 3rd ventricle <br />The thalamus extends from the anterior commissure to the inferior base of the pineal gland <br />Figure 14.11 The Thalamus <br />The hypothalamus <br />Extends from the optic chiasm to the posterior portions of the mamillary bodies <br />The mamillary bodies process sensory information and are responsible for the motor movements associated with swallowing and chewing <br />The infundibulum <br />Area immediately posterior to the optic chiasm <br />Extends inferiorly from the floor of the hypothalamus <br />This is a small narrow stalk <br />Connects to the pituitary glands <br /> <br />What stimulates the hypothalamus? <br />Sensory information from the cerebrum, brain stem, and spinal cord <br />Changes in the composition of CSF <br />Chemical changes in circulating blood <br /> <br />Subconscious control of the skeletal muscle contractions <br />Directs somatic motor patterns associated with rage, pleasure, pain, and sexual arousal <br /> <br />Control of autonomic functions <br />Adjusts activity of the pons <br />Adjusts centers in the medulla which regulate heart beat, blood pressure, and digestive functions <br /> <br />Coordinates activities of nervous and endocrine systems <br />It inhibits or stimulates endocrine cells in the pituitary gland through the production of regulatory hormones <br />Anterior lobe of the pituitary <br /> <br />Secretion of hormones <br />ADH <br />Oxytocin <br />Passed onto the posterior lobe of the pituitary <br />Production of emotions and drives <br />Conscious and subconscious behavior patterns <br />Feeding <br />Thirst <br />"drives" <br /> <br />Coordinate Voluntary and involuntary functions <br />Increase in heart rate and blood pressure in fight or flight response <br /> <br />Regulate body temperature <br />Regulates CNS activities to keep body temperature normal <br />Body temp falls, preoptic center signals an autonomic cente, a vasomotor center in the medulla to regulate the peripheral blood vessels <br /> <br />Coordination of Circadian Rhythms <br />Day and night cycle <br />Sleep and wake cycle <br />Through the activity of the pineal gland and the reticular formation <br />Functions of the the hypothalamus in review <br />Controls somatic motor activities at the subconscious level <br />Controls autonomic function <br />Coordinates activities of the endocrine and nervous systems <br />Secretes hormones <br />Produces emotions and behavioral drives <br />Coordinates voluntary and autonomic functions <br />Regulates body temperature <br />Coordinates circadian cycles of activity <br />Figure 14.12 The Hypothalamus in Sagittal Section <br />Figure 14.12 The Hypothalamus in Sagittal Section <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109528964369493053?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095289220245342182004-09-15T15:56:00.000-07:002004-09-15T16:00:20.246-07:00Chapter 12, part 2 <br />Neural tissue <br />SECTION 12-4 Neurophysiology: Ions and Electrical Signals <br />Important membrane processes <br />Resting potential <br />Graded potential <br />Action potential <br />Synaptic activity <br />Information process <br />Resting potential <br />A neural activities begin with a change in the resting potential <br /> <br />Graded potential <br />A typical localized stimulus with a strength decreasing from the site or origin <br />Action Potential <br />Electrical impulse which is propagated across the surface of the membrane but does not diminish in its strength from the source <br />Synaptic Activity <br />This involves the release of neurotransmitters such as Ach <br />These bind to the postsynaptic cell membrane <br />A graded response is then produced <br />Information processing <br />The response of a postsynaptic cell depends on which receptors are activated <br /> <br />Membrane Potential concepts <br />The intracellular and the extracellular fluids differ in their ionic concentrations <br />High Na and chloride ions outside the cell <br />High potassium ion concentration inside the cell <br />The nerve cell membrane is sided <br />Ions are not free to move easily from one side to another must move through leak channels <br />This is true of a cell which is in the resting potential state <br /> <br />Concepts continued <br />Key: <br />There is this sided membrane <br />There is not a equal number of positive and negative changes on each side of the membrane <br />It is easier for the potassium ions to move out into the ECF then it is for the sodium to move into the cell <br />This is why the cell pumps out two sodium ions and pumps in three potassium ions <br />This relationship of unequal charge distribution is responsible for the excess positive charges on the outside of the membrane <br /> <br />Passive forces <br />Classified as being <br />Chemical gradient <br />Electrical gradients <br />Chemical gradients <br />The driving forces here are the chemical identity of the ion in question <br />This is passive diffusion, from high concentration to low concentration without the involvement of energy expenditure <br />Electrical Gradients <br />Because the cell membrane is more permeable to potassium ions than sodium ions, there is a net negative charge inside of the membrane due to the presence of negatively charged proteins <br />This membrane potential difference is measured in mV volts and for nerve cells is – 70 mV <br />It is the cell membrane which separates the positive and negative volts from each other <br /> <br />The electrochemical gradient <br />This potential can oppose or reinforce the chemical gradient <br />This is a measure of those forces, opposites attract and identical repel <br />In order for the charge to be negative inside the cell, this means that the chemical gradient is the important driving force over the electrical <br /> <br /> <br />Active forces: Sodium Potassium Pump <br />An ATPase <br />Pumps out three sodium for every three K pumps back in <br />This is due to the fact that potassium leaks more easily then sodium leaks in through its leak channels <br />Figure 12.11 An Introduction to the Resting Potential <br />Figure 12.12 Electrochemical Gradients <br />What is resting potential? <br />It is the mV differences between the inside and the outside of the cell due to concentration differences <br />This is measured when the cell is undisturbed <br />Remember that this mV potential changes when membrane permeability changes <br /> <br />Membrane Channel classifications <br />Passive or leak channels <br />Active or gated channels <br /> <br />Chemically regulated channels <br /> <br />Changes in the transmembrane potential <br />Membrane contains <br />Passive (leak) channels that are always open <br />Active (gated) channels that open and close in response to stimuli <br />Figure 12.13 Gated Channels <br />Three types of active channels <br />Chemically regulated channels <br />Voltage-regulated channels <br />Mechanically regulated channels <br />Chemically regulated channels <br />Found most of the time on the dendrites and cell body of a neuron <br />Open or close when they bind neurotransmitters <br />Wide spread along the surface of neurons <br /> <br /> <br />Voltage regulated <br />Properties of an excitable membrane <br />Typically found on axons and synaptic terminals <br />Capable of generating an action potential <br />Sodium, potassium, and calcium <br />Mechanically regulated channels <br />These respond to a mechanical stress <br />Typically found on dendrites <br />Typically those that respond to: <br />Pressure <br />Touch <br />vibration <br />Graded potential: Sodium ions <br />A change in potential that decreases with distance <br />Localized depolarization or hyperpolarization <br />The result of a stimulus acting on a gated channel <br />The more channels that open, the stronger the response <br /> <br />Graded Potentials: Potassium <br />Opening this channel has the opposite effect <br />Have hyperpolarization <br />This makes the inside of the membrane more negative <br />This makes the membrane less likely to respond <br /> <br />Information and Graded Potentials <br />Each neuron on the dendritic side receives a stimuli which responds as a graded potential <br />Figure 12.14 Graded Potentials <br />Figure 12.14 Graded Potentials <br />Figure 12.15 Depolarization and Hyperpolarization <br />Action Potential <br />Appears when region of excitable membrane depolarizes to threshold <br />Steps involved <br />Membrane depolarization and sodium channel activation <br />Sodium channel inactivation <br />Potassium channel activation <br />Return to normal permeability <br />Action Potentials <br />These are propagated changes in the transmembrane potential <br />Once started will affect the entire length of the membrane <br /> <br />How does it start? <br />The voltage gated sodium channels must open first <br />The sodium ions move across the membrane <br />This changes the voltage difference across the membrane at this site <br />It then starts the opening of adjacent voltage gated channels <br />This resembles a dominoes effect <br /> <br />All of none principle <br />The initial stimulus must be large enough to open the voltage regulated sodium channels <br />The impulse can only be passed on when the threshold is exceeded <br />It is the graded local potential which is responsible for the action potential to take place <br /> <br /> <br />Generation of action potentials <br />Depolarization to threshold <br />Activation of sodium channels and rapid depolarization <br />Inactivation of the sodium channels and the activation of the potassium channels <br />Return to normal permeability <br /> <br />Depolarization to threshold <br />An area of excitable membrane must be depolarized <br /> <br />Activation of Sodium channels and rapid depolarization <br />When threshold is reached, the sodium channels open <br />Now the large electrochemical chemical gradient becomes important <br />The positively charged sodium ions move inside the membrane because they are attracted to the negative charges on the inside of the membrane <br />The voltage across the membrane is now positive <br /> <br />Inactivation of sodium channels/ activation of potassium channels <br />At ~ 30 mV the potassium channels open <br />Interior of the cell membrane has an excess of positive charges <br />Here the electrical and chemical gradients favor the movement of potassium ions out of the cell <br />This sudden loss sodium ions pushes the membrane potential back to resting levels <br /> <br />Normal permeability <br />This occurs only after a brief state of hyperpolarization <br /> <br />Refractory Period <br />The time that the action potential begins and until the normal resting potential has been established the membrane will not respond normally to an additional stimuli <br />Divided into absolute and relative refractory segments <br /> <br />Absolute refractory period <br />When all of the sodium regulated channels are open or inactivated <br /> <br /> <br />Relative refractory period <br />Begin when the sodium channels regain their normal; resting condition <br />Here another action potential can occur only if the stimuli is additionally strong <br />This is needed to counter the potassium ion loss <br /> <br /> <br />Sodium Potassium pump <br />This pumps uses ATP <br />An enzyme called ATPase is required <br />This keep the balance of sodium and potassium ions proper on the membrane side <br />There are 3 sodium on the outside for every 2 potassium ions on the inside <br />Job is to return the sodium potassium extracellular and intracellular concentrations to prestimulation levels <br /> <br />Propagation of Action potentials <br />Graded potential is in a short section of the membrane <br />Action potential extends across the length of the entire membrane <br />The same events take place over and over <br />This process is called propagation <br />Figure 12.16 The Generation of an Action Potential <br />Figure 12.17 The Generation of an Action Potential <br />Characteristics of action potentials <br />Generation of action potential follows all-or-none principle <br />Refractory period lasts from time action potential begins until normal resting potential returns <br />Continuous propagation <br />spread of action potential across entire membrane in series of small steps <br />salutatory propagation <br />action potential spreads from node to node, skipping internodal membrane <br />Figure 12.17 Propagation of an Action Potential along an Unmyelinated Axon <br />Saltatory Propagation <br />Occurs in a myelinated axon <br />This means that only the nodes can respond to a stimuli <br />This means the signal jumps from one internode to another <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part I <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part II <br />Axon classification <br />Type A fibers: largest of the axons, myelinated, 300 mph <br />Type B fibers: myelinated, smaller, 40 mph <br />Type C fibers: unmyleinated, 2 mph <br />Based on diameter, myelination and propagation speed <br />Where do you find them? <br />Type A fibers carry sensory information to CNS about position, balance, delicate touch, pressure on skin, also include the motor neurons <br />Type B and C carry information to the CNS about temperature, pressure, pain, general touch and pressure and carry instructions to smooth and cardiac muscle and other peripheral effectors <br />Type C carries most of the sensory information to the CNS <br />Muscle action potential versus neural action potential <br />Muscle tissue has higher resting potential <br />Muscle tissue action potentials are longer lasting <br />Muscle tissue has slower propagation of action potentials <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109528922024534218?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095288672254916382004-09-15T15:42:00.002-07:002004-09-15T15:51:12.253-07:00Chapter 12, part 2 <br />Neural tissue <br />SECTION 12-4 Neurophysiology: Ions and Electrical Signals <br />Important membrane processes <br />Resting potential <br />Graded potential <br />Action potential <br />Synaptic activity <br />Information process <br />Resting potential <br />A neural activities begin with a change in the resting potential <br /> <br />Graded potential <br />A typical localized stimulus with a strength decreasing from the site or origin <br />Action Potential <br />Electrical impulse which is propagated across the surface of the membrane but does not diminish in its strength from the source <br />Synaptic Activity <br />This involves the release of neurotransmitters such as Ach <br />These bind to the postsynaptic cell membrane <br />A graded response is then produced <br />Information processing <br />The response of a postsynaptic cell depends on which receptors are activated <br /> <br />Membrane Potential concepts <br />The intracellular and the extracellular fluids differ in their ionic concentrations <br />High Na and chloride ions outside the cell <br />High potassium ion concentration inside the cell <br />The nerve cell membrane is sided <br />Ions are not free to move easily from one side to another must move through leak channels <br />This is true of a cell which is in the resting potential state <br /> <br />Concepts continued <br />Key: <br />There is this sided membrane <br />There is not a equal number of positive and negative changes on each side of the membrane <br />It is easier for the potassium ions to move out into the ECF then it is for the sodium to move into the cell <br />This is why the cell pumps out two sodium ions and pumps in three potassium ions <br />This relationship of unequal charge distribution is responsible for the excess positive charges on the outside of the membrane <br /> <br />Passive forces <br />Classified as being <br />Chemical gradient <br />Electrical gradients <br />Chemical gradients <br />The driving forces here are the chemical identity of the ion in question <br />This is passive diffusion, from high concentration to low concentration without the involvement of energy expenditure <br />Electrical Gradients <br />Because the cell membrane is more permeable to potassium ions than sodium ions, there is a net negative charge inside of the membrane due to the presence of negatively charged proteins <br />This membrane potential difference is measured in mV volts and for nerve cells is – 70 mV <br />It is the cell membrane which separates the positive and negative volts from each other <br /> <br />The electrochemical gradient <br />This potential can oppose or reinforce the chemical gradient <br />This is a measure of those forces, opposites attract and identical repel <br />In order for the charge to be negative inside the cell, this means that the chemical gradient is the important driving force over the electrical <br /> <br /> <br />Active forces: Sodium Potassium Pump <br />An ATPase <br />Pumps out three sodium for every three K pumps back in <br />This is due to the fact that potassium leaks more easily then sodium leaks in through its leak channels <br />Figure 12.11 An Introduction to the Resting Potential <br />Figure 12.12 Electrochemical Gradients <br />What is resting potential? <br />It is the mV differences between the inside and the outside of the cell due to concentration differences <br />This is measured when the cell is undisturbed <br />Remember that this mV potential changes when membrane permeability changes <br /> <br />Membrane Channel classifications <br />Passive or leak channels <br />Active or gated channels <br /> <br />Chemically regulated channels <br /> <br />Changes in the transmembrane potential <br />Membrane contains <br />Passive (leak) channels that are always open <br />Active (gated) channels that open and close in response to stimuli <br />Figure 12.13 Gated Channels <br />Three types of active channels <br />Chemically regulated channels <br />Voltage-regulated channels <br />Mechanically regulated channels <br />Chemically regulated channels <br />Found most of the time on the dendrites and cell body of a neuron <br />Open or close when they bind neurotransmitters <br />Wide spread along the surface of neurons <br /> <br /> <br />Voltage regulated <br />Properties of an excitable membrane <br />Typically found on axons and synaptic terminals <br />Capable of generating an action potential <br />Sodium, potassium, and calcium <br />Mechanically regulated channels <br />These respond to a mechanical stress <br />Typically found on dendrites <br />Typically those that respond to: <br />Pressure <br />Touch <br />vibration <br />Graded potential: Sodium ions <br />A change in potential that decreases with distance <br />Localized depolarization or hyperpolarization <br />The result of a stimulus acting on a gated channel <br />The more channels that open, the stronger the response <br /> <br />Graded Potentials: Potassium <br />Opening this channel has the opposite effect <br />Have hyperpolarization <br />This makes the inside of the membrane more negative <br />This makes the membrane less likely to respond <br /> <br />Information and Graded Potentials <br />Each neuron on the dendritic side receives a stimuli which responds as a graded potential <br />Figure 12.14 Graded Potentials <br />Figure 12.14 Graded Potentials <br />Figure 12.15 Depolarization and Hyperpolarization <br />Action Potential <br />Appears when region of excitable membrane depolarizes to threshold <br />Steps involved <br />Membrane depolarization and sodium channel activation <br />Sodium channel inactivation <br />Potassium channel activation <br />Return to normal permeability <br />Action Potentials <br />These are propagated changes in the transmembrane potential <br />Once started will affect the entire length of the membrane <br /> <br />How does it start? <br />The voltage gated sodium channels must open first <br />The sodium ions move across the membrane <br />This changes the voltage difference across the membrane at this site <br />It then starts the opening of adjacent voltage gated channels <br />This resembles a dominoes effect <br /> <br />All of none principle <br />The initial stimulus must be large enough to open the voltage regulated sodium channels <br />The impulse can only be passed on when the threshold is exceeded <br />It is the graded local potential which is responsible for the action potential to take place <br /> <br /> <br />Generation of action potentials <br />Depolarization to threshold <br />Activation of sodium channels and rapid depolarization <br />Inactivation of the sodium channels and the activation of the potassium channels <br />Return to normal permeability <br /> <br />Depolarization to threshold <br />An area of excitable membrane must be depolarized <br /> <br />Activation of Sodium channels and rapid depolarization <br />When threshold is reached, the sodium channels open <br />Now the large electrochemical chemical gradient becomes important <br />The positively charged sodium ions move inside the membrane because they are attracted to the negative charges on the inside of the membrane <br />The voltage across the membrane is now positive <br /> <br />Inactivation of sodium channels/ activation of potassium channels <br />At ~ 30 mV the potassium channels open <br />Interior of the cell membrane has an excess of positive charges <br />Here the electrical and chemical gradients favor the movement of potassium ions out of the cell <br />This sudden loss sodium ions pushes the membrane potential back to resting levels <br /> <br />Normal permeability <br />This occurs only after a brief state of hyperpolarization <br /> <br />Refractory Period <br />The time that the action potential begins and until the normal resting potential has been established the membrane will not respond normally to an additional stimuli <br />Divided into absolute and relative refractory segments <br /> <br />Absolute refractory period <br />When all of the sodium regulated channels are open or inactivated <br /> <br /> <br />Relative refractory period <br />Begin when the sodium channels regain their normal; resting condition <br />Here another action potential can occur only if the stimuli is additionally strong <br />This is needed to counter the potassium ion loss <br /> <br /> <br />Sodium Potassium pump <br />This pumps uses ATP <br />An enzyme called ATPase is required <br />This keep the balance of sodium and potassium ions proper on the membrane side <br />There are 3 sodium on the outside for every 2 potassium ions on the inside <br />Job is to return the sodium potassium extracellular and intracellular concentrations to prestimulation levels <br /> <br />Propagation of Action potentials <br />Graded potential is in a short section of the membrane <br />Action potential extends across the length of the entire membrane <br />The same events take place over and over <br />This process is called propagation <br />Figure 12.16 The Generation of an Action Potential <br />Figure 12.17 The Generation of an Action Potential <br />Characteristics of action potentials <br />Generation of action potential follows all-or-none principle <br />Refractory period lasts from time action potential begins until normal resting potential returns <br />Continuous propagation <br />spread of action potential across entire membrane in series of small steps <br />salutatory propagation <br />action potential spreads from node to node, skipping internodal membrane <br />Figure 12.17 Propagation of an Action Potential along an Unmyelinated Axon <br />Saltatory Propagation <br />Occurs in a myelinated axon <br />This means that only the nodes can respond to a stimuli <br />This means the signal jumps from one internode to another <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part I <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part II <br />Axon classification <br />Type A fibers: largest of the axons, myelinated, 300 mph <br />Type B fibers: myelinated, smaller, 40 mph <br />Type C fibers: unmyleinated, 2 mph <br />Based on diameter, myelination and propagation speed <br />Where do you find them? <br />Type A fibers carry sensory information to CNS about position, balance, delicate touch, pressure on skin, also include the motor neurons <br />Type B and C carry information to the CNS about temperature, pressure, pain, general touch and pressure and carry instructions to smooth and cardiac muscle and other peripheral effectors <br />Type C carries most of the sensory information to the CNS <br />Muscle action potential versus neural action potential <br />Muscle tissue has higher resting potential <br />Muscle tissue action potentials are longer lasting <br />Muscle tissue has slower propagation of action potentials <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109528867225491638?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095288650891634042004-09-15T15:42:00.001-07:002004-09-15T15:50:50.893-07:00Chapter 12, part 2 <br />Neural tissue <br />SECTION 12-4 Neurophysiology: Ions and Electrical Signals <br />Important membrane processes <br />Resting potential <br />Graded potential <br />Action potential <br />Synaptic activity <br />Information process <br />Resting potential <br />A neural activities begin with a change in the resting potential <br /> <br />Graded potential <br />A typical localized stimulus with a strength decreasing from the site or origin <br />Action Potential <br />Electrical impulse which is propagated across the surface of the membrane but does not diminish in its strength from the source <br />Synaptic Activity <br />This involves the release of neurotransmitters such as Ach <br />These bind to the postsynaptic cell membrane <br />A graded response is then produced <br />Information processing <br />The response of a postsynaptic cell depends on which receptors are activated <br /> <br />Membrane Potential concepts <br />The intracellular and the extracellular fluids differ in their ionic concentrations <br />High Na and chloride ions outside the cell <br />High potassium ion concentration inside the cell <br />The nerve cell membrane is sided <br />Ions are not free to move easily from one side to another must move through leak channels <br />This is true of a cell which is in the resting potential state <br /> <br />Concepts continued <br />Key: <br />There is this sided membrane <br />There is not a equal number of positive and negative changes on each side of the membrane <br />It is easier for the potassium ions to move out into the ECF then it is for the sodium to move into the cell <br />This is why the cell pumps out two sodium ions and pumps in three potassium ions <br />This relationship of unequal charge distribution is responsible for the excess positive charges on the outside of the membrane <br /> <br />Passive forces <br />Classified as being <br />Chemical gradient <br />Electrical gradients <br />Chemical gradients <br />The driving forces here are the chemical identity of the ion in question <br />This is passive diffusion, from high concentration to low concentration without the involvement of energy expenditure <br />Electrical Gradients <br />Because the cell membrane is more permeable to potassium ions than sodium ions, there is a net negative charge inside of the membrane due to the presence of negatively charged proteins <br />This membrane potential difference is measured in mV volts and for nerve cells is – 70 mV <br />It is the cell membrane which separates the positive and negative volts from each other <br /> <br />The electrochemical gradient <br />This potential can oppose or reinforce the chemical gradient <br />This is a measure of those forces, opposites attract and identical repel <br />In order for the charge to be negative inside the cell, this means that the chemical gradient is the important driving force over the electrical <br /> <br /> <br />Active forces: Sodium Potassium Pump <br />An ATPase <br />Pumps out three sodium for every three K pumps back in <br />This is due to the fact that potassium leaks more easily then sodium leaks in through its leak channels <br />Figure 12.11 An Introduction to the Resting Potential <br />Figure 12.12 Electrochemical Gradients <br />What is resting potential? <br />It is the mV differences between the inside and the outside of the cell due to concentration differences <br />This is measured when the cell is undisturbed <br />Remember that this mV potential changes when membrane permeability changes <br /> <br />Membrane Channel classifications <br />Passive or leak channels <br />Active or gated channels <br /> <br />Chemically regulated channels <br /> <br />Changes in the transmembrane potential <br />Membrane contains <br />Passive (leak) channels that are always open <br />Active (gated) channels that open and close in response to stimuli <br />Figure 12.13 Gated Channels <br />Three types of active channels <br />Chemically regulated channels <br />Voltage-regulated channels <br />Mechanically regulated channels <br />Chemically regulated channels <br />Found most of the time on the dendrites and cell body of a neuron <br />Open or close when they bind neurotransmitters <br />Wide spread along the surface of neurons <br /> <br /> <br />Voltage regulated <br />Properties of an excitable membrane <br />Typically found on axons and synaptic terminals <br />Capable of generating an action potential <br />Sodium, potassium, and calcium <br />Mechanically regulated channels <br />These respond to a mechanical stress <br />Typically found on dendrites <br />Typically those that respond to: <br />Pressure <br />Touch <br />vibration <br />Graded potential: Sodium ions <br />A change in potential that decreases with distance <br />Localized depolarization or hyperpolarization <br />The result of a stimulus acting on a gated channel <br />The more channels that open, the stronger the response <br /> <br />Graded Potentials: Potassium <br />Opening this channel has the opposite effect <br />Have hyperpolarization <br />This makes the inside of the membrane more negative <br />This makes the membrane less likely to respond <br /> <br />Information and Graded Potentials <br />Each neuron on the dendritic side receives a stimuli which responds as a graded potential <br />Figure 12.14 Graded Potentials <br />Figure 12.14 Graded Potentials <br />Figure 12.15 Depolarization and Hyperpolarization <br />Action Potential <br />Appears when region of excitable membrane depolarizes to threshold <br />Steps involved <br />Membrane depolarization and sodium channel activation <br />Sodium channel inactivation <br />Potassium channel activation <br />Return to normal permeability <br />Action Potentials <br />These are propagated changes in the transmembrane potential <br />Once started will affect the entire length of the membrane <br /> <br />How does it start? <br />The voltage gated sodium channels must open first <br />The sodium ions move across the membrane <br />This changes the voltage difference across the membrane at this site <br />It then starts the opening of adjacent voltage gated channels <br />This resembles a dominoes effect <br /> <br />All of none principle <br />The initial stimulus must be large enough to open the voltage regulated sodium channels <br />The impulse can only be passed on when the threshold is exceeded <br />It is the graded local potential which is responsible for the action potential to take place <br /> <br /> <br />Generation of action potentials <br />Depolarization to threshold <br />Activation of sodium channels and rapid depolarization <br />Inactivation of the sodium channels and the activation of the potassium channels <br />Return to normal permeability <br /> <br />Depolarization to threshold <br />An area of excitable membrane must be depolarized <br /> <br />Activation of Sodium channels and rapid depolarization <br />When threshold is reached, the sodium channels open <br />Now the large electrochemical chemical gradient becomes important <br />The positively charged sodium ions move inside the membrane because they are attracted to the negative charges on the inside of the membrane <br />The voltage across the membrane is now positive <br /> <br />Inactivation of sodium channels/ activation of potassium channels <br />At ~ 30 mV the potassium channels open <br />Interior of the cell membrane has an excess of positive charges <br />Here the electrical and chemical gradients favor the movement of potassium ions out of the cell <br />This sudden loss sodium ions pushes the membrane potential back to resting levels <br /> <br />Normal permeability <br />This occurs only after a brief state of hyperpolarization <br /> <br />Refractory Period <br />The time that the action potential begins and until the normal resting potential has been established the membrane will not respond normally to an additional stimuli <br />Divided into absolute and relative refractory segments <br /> <br />Absolute refractory period <br />When all of the sodium regulated channels are open or inactivated <br /> <br /> <br />Relative refractory period <br />Begin when the sodium channels regain their normal; resting condition <br />Here another action potential can occur only if the stimuli is additionally strong <br />This is needed to counter the potassium ion loss <br /> <br /> <br />Sodium Potassium pump <br />This pumps uses ATP <br />An enzyme called ATPase is required <br />This keep the balance of sodium and potassium ions proper on the membrane side <br />There are 3 sodium on the outside for every 2 potassium ions on the inside <br />Job is to return the sodium potassium extracellular and intracellular concentrations to prestimulation levels <br /> <br />Propagation of Action potentials <br />Graded potential is in a short section of the membrane <br />Action potential extends across the length of the entire membrane <br />The same events take place over and over <br />This process is called propagation <br />Figure 12.16 The Generation of an Action Potential <br />Figure 12.17 The Generation of an Action Potential <br />Characteristics of action potentials <br />Generation of action potential follows all-or-none principle <br />Refractory period lasts from time action potential begins until normal resting potential returns <br />Continuous propagation <br />spread of action potential across entire membrane in series of small steps <br />salutatory propagation <br />action potential spreads from node to node, skipping internodal membrane <br />Figure 12.17 Propagation of an Action Potential along an Unmyelinated Axon <br />Saltatory Propagation <br />Occurs in a myelinated axon <br />This means that only the nodes can respond to a stimuli <br />This means the signal jumps from one internode to another <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part I <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part II <br />Axon classification <br />Type A fibers: largest of the axons, myelinated, 300 mph <br />Type B fibers: myelinated, smaller, 40 mph <br />Type C fibers: unmyleinated, 2 mph <br />Based on diameter, myelination and propagation speed <br />Where do you find them? <br />Type A fibers carry sensory information to CNS about position, balance, delicate touch, pressure on skin, also include the motor neurons <br />Type B and C carry information to the CNS about temperature, pressure, pain, general touch and pressure and carry instructions to smooth and cardiac muscle and other peripheral effectors <br />Type C carries most of the sensory information to the CNS <br />Muscle action potential versus neural action potential <br />Muscle tissue has higher resting potential <br />Muscle tissue action potentials are longer lasting <br />Muscle tissue has slower propagation of action potentials <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109528865089163404?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com1tag:blogger.com,1999:blog-7191541.post-1095288535490309532004-09-15T15:42:00.000-07:002004-09-15T15:48:55.490-07:00Chapter 12, part 2 <br />Neural tissue <br />SECTION 12-4 Neurophysiology: Ions and Electrical Signals <br />Important membrane processes <br />Resting potential <br />Graded potential <br />Action potential <br />Synaptic activity <br />Information process <br />Resting potential <br />A neural activities begin with a change in the resting potential <br /> <br />Graded potential <br />A typical localized stimulus with a strength decreasing from the site or origin <br />Action Potential <br />Electrical impulse which is propagated across the surface of the membrane but does not diminish in its strength from the source <br />Synaptic Activity <br />This involves the release of neurotransmitters such as Ach <br />These bind to the postsynaptic cell membrane <br />A graded response is then produced <br />Information processing <br />The response of a postsynaptic cell depends on which receptors are activated <br /> <br />Membrane Potential concepts <br />The intracellular and the extracellular fluids differ in their ionic concentrations <br />High Na and chloride ions outside the cell <br />High potassium ion concentration inside the cell <br />The nerve cell membrane is sided <br />Ions are not free to move easily from one side to another must move through leak channels <br />This is true of a cell which is in the resting potential state <br /> <br />Concepts continued <br />Key: <br />There is this sided membrane <br />There is not a equal number of positive and negative changes on each side of the membrane <br />It is easier for the potassium ions to move out into the ECF then it is for the sodium to move into the cell <br />This is why the cell pumps out two sodium ions and pumps in three potassium ions <br />This relationship of unequal charge distribution is responsible for the excess positive charges on the outside of the membrane <br /> <br />Passive forces <br />Classified as being <br />Chemical gradient <br />Electrical gradients <br />Chemical gradients <br />The driving forces here are the chemical identity of the ion in question <br />This is passive diffusion, from high concentration to low concentration without the involvement of energy expenditure <br />Electrical Gradients <br />Because the cell membrane is more permeable to potassium ions than sodium ions, there is a net negative charge inside of the membrane due to the presence of negatively charged proteins <br />This membrane potential difference is measured in mV volts and for nerve cells is – 70 mV <br />It is the cell membrane which separates the positive and negative volts from each other <br /> <br />The electrochemical gradient <br />This potential can oppose or reinforce the chemical gradient <br />This is a measure of those forces, opposites attract and identical repel <br />In order for the charge to be negative inside the cell, this means that the chemical gradient is the important driving force over the electrical <br /> <br /> <br />Active forces: Sodium Potassium Pump <br />An ATPase <br />Pumps out three sodium for every three K pumps back in <br />This is due to the fact that potassium leaks more easily then sodium leaks in through its leak channels <br />Figure 12.11 An Introduction to the Resting Potential <br />Figure 12.12 Electrochemical Gradients <br />What is resting potential? <br />It is the mV differences between the inside and the outside of the cell due to concentration differences <br />This is measured when the cell is undisturbed <br />Remember that this mV potential changes when membrane permeability changes <br /> <br />Membrane Channel classifications <br />Passive or leak channels <br />Active or gated channels <br /> <br />Chemically regulated channels <br /> <br />Changes in the transmembrane potential <br />Membrane contains <br />Passive (leak) channels that are always open <br />Active (gated) channels that open and close in response to stimuli <br />Figure 12.13 Gated Channels <br />Three types of active channels <br />Chemically regulated channels <br />Voltage-regulated channels <br />Mechanically regulated channels <br />Chemically regulated channels <br />Found most of the time on the dendrites and cell body of a neuron <br />Open or close when they bind neurotransmitters <br />Wide spread along the surface of neurons <br /> <br /> <br />Voltage regulated <br />Properties of an excitable membrane <br />Typically found on axons and synaptic terminals <br />Capable of generating an action potential <br />Sodium, potassium, and calcium <br />Mechanically regulated channels <br />These respond to a mechanical stress <br />Typically found on dendrites <br />Typically those that respond to: <br />Pressure <br />Touch <br />vibration <br />Graded potential: Sodium ions <br />A change in potential that decreases with distance <br />Localized depolarization or hyperpolarization <br />The result of a stimulus acting on a gated channel <br />The more channels that open, the stronger the response <br /> <br />Graded Potentials: Potassium <br />Opening this channel has the opposite effect <br />Have hyperpolarization <br />This makes the inside of the membrane more negative <br />This makes the membrane less likely to respond <br /> <br />Information and Graded Potentials <br />Each neuron on the dendritic side receives a stimuli which responds as a graded potential <br />Figure 12.14 Graded Potentials <br />Figure 12.14 Graded Potentials <br />Figure 12.15 Depolarization and Hyperpolarization <br />Action Potential <br />Appears when region of excitable membrane depolarizes to threshold <br />Steps involved <br />Membrane depolarization and sodium channel activation <br />Sodium channel inactivation <br />Potassium channel activation <br />Return to normal permeability <br />Action Potentials <br />These are propagated changes in the transmembrane potential <br />Once started will affect the entire length of the membrane <br /> <br />How does it start? <br />The voltage gated sodium channels must open first <br />The sodium ions move across the membrane <br />This changes the voltage difference across the membrane at this site <br />It then starts the opening of adjacent voltage gated channels <br />This resembles a dominoes effect <br /> <br />All of none principle <br />The initial stimulus must be large enough to open the voltage regulated sodium channels <br />The impulse can only be passed on when the threshold is exceeded <br />It is the graded local potential which is responsible for the action potential to take place <br /> <br /> <br />Generation of action potentials <br />Depolarization to threshold <br />Activation of sodium channels and rapid depolarization <br />Inactivation of the sodium channels and the activation of the potassium channels <br />Return to normal permeability <br /> <br />Depolarization to threshold <br />An area of excitable membrane must be depolarized <br /> <br />Activation of Sodium channels and rapid depolarization <br />When threshold is reached, the sodium channels open <br />Now the large electrochemical chemical gradient becomes important <br />The positively charged sodium ions move inside the membrane because they are attracted to the negative charges on the inside of the membrane <br />The voltage across the membrane is now positive <br /> <br />Inactivation of sodium channels/ activation of potassium channels <br />At ~ 30 mV the potassium channels open <br />Interior of the cell membrane has an excess of positive charges <br />Here the electrical and chemical gradients favor the movement of potassium ions out of the cell <br />This sudden loss sodium ions pushes the membrane potential back to resting levels <br /> <br />Normal permeability <br />This occurs only after a brief state of hyperpolarization <br /> <br />Refractory Period <br />The time that the action potential begins and until the normal resting potential has been established the membrane will not respond normally to an additional stimuli <br />Divided into absolute and relative refractory segments <br /> <br />Absolute refractory period <br />When all of the sodium regulated channels are open or inactivated <br /> <br /> <br />Relative refractory period <br />Begin when the sodium channels regain their normal; resting condition <br />Here another action potential can occur only if the stimuli is additionally strong <br />This is needed to counter the potassium ion loss <br /> <br /> <br />Sodium Potassium pump <br />This pumps uses ATP <br />An enzyme called ATPase is required <br />This keep the balance of sodium and potassium ions proper on the membrane side <br />There are 3 sodium on the outside for every 2 potassium ions on the inside <br />Job is to return the sodium potassium extracellular and intracellular concentrations to prestimulation levels <br /> <br />Propagation of Action potentials <br />Graded potential is in a short section of the membrane <br />Action potential extends across the length of the entire membrane <br />The same events take place over and over <br />This process is called propagation <br />Figure 12.16 The Generation of an Action Potential <br />Figure 12.17 The Generation of an Action Potential <br />Characteristics of action potentials <br />Generation of action potential follows all-or-none principle <br />Refractory period lasts from time action potential begins until normal resting potential returns <br />Continuous propagation <br />spread of action potential across entire membrane in series of small steps <br />salutatory propagation <br />action potential spreads from node to node, skipping internodal membrane <br />Figure 12.17 Propagation of an Action Potential along an Unmyelinated Axon <br />Saltatory Propagation <br />Occurs in a myelinated axon <br />This means that only the nodes can respond to a stimuli <br />This means the signal jumps from one internode to another <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part I <br />Figure 12.18 Saltatory Propagation along a Myelinated Axon Part II <br />Axon classification <br />Type A fibers: largest of the axons, myelinated, 300 mph <br />Type B fibers: myelinated, smaller, 40 mph <br />Type C fibers: unmyleinated, 2 mph <br />Based on diameter, myelination and propagation speed <br />Where do you find them? <br />Type A fibers carry sensory information to CNS about position, balance, delicate touch, pressure on skin, also include the motor neurons <br />Type B and C carry information to the CNS about temperature, pressure, pain, general touch and pressure and carry instructions to smooth and cardiac muscle and other peripheral effectors <br />Type C carries most of the sensory information to the CNS <br />Muscle action potential versus neural action potential <br />Muscle tissue has higher resting potential <br />Muscle tissue action potentials are longer lasting <br />Muscle tissue has slower propagation of action potentials <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109528853549030953?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095196888369586122004-09-14T14:20:00.000-07:002004-09-14T14:21:28.370-07:00Chapter 13, part 3 <br />The Spinal Cord and Spinal Nerves <br />SECTION 13-4 Principles of Functional Organization <br />General information <br />The human body has 10 million sensory neurons <br />500,000 million motor neurons <br />20 billion interneurons <br />General organization <br />Sensory neurons <br />Deliver information to CNS <br />Motor neurons <br />Distribute commands to peripheral effectors <br />Interneurons <br />Interpret information and coordinate responses <br />Neuronal pools <br />The billions of interneurons are organized into much smaller units called the neuronal pools <br />Which are the functional group of interconnected neurons <br />Each have a limited number of input sources and output destinations <br />Each may contain both inhibitory and excitatory neurons <br />The output of one neuronal pool may be inhibitory or excitatory on another neuronal pool <br />Types of neuronal pools <br />Neural circuit patterns <br />Divergence <br />Convergence <br />Serial processing <br />Parallel processing <br />Reverberation <br />Figure 13.15 The Organization of Neuronal Pools <br />Divergence <br />This is the spread of information from one neuron to many neurons <br />Or form one pool to many pools <br />Often found where sensory neurons bring information to the CNS for the information to be distributed to neuronal pools in the spinal cord and the brain <br /> <br />Convergence <br />Several neurons synapse on the same post synaptic neuron <br />This means that several patterns of activity in a presynaptic neuron can therefore have the same effect on the same postsynaptic neuron <br />This means that both conscious and subconscious activity can be directed to the same muscle <br />diaphragm <br />Serial processing <br />Information being relayed in a stepwise fashion <br />Typical of sensory processing when information is moved form one part of the brain to the other <br /> <br />Parallel Processing <br />This occurs when several neuronal pools access the same information at the same time <br />Typical of a pain reflex arc as when you step on a sharp nail <br /> <br /> <br />Reverberation <br />Often described as a form of positive feedback <br />This causes an amplification of a signal <br />Common examples <br />Normal breathing <br />Muscle coordination <br />Maintain conscious <br />An introduction to reflexes <br />Reflexes are rapid automatic responses to stimuli to maintain homeostasis by making rapid adjustments in the functions of organs and organ systems <br />A response with little variability <br />The same response is usually produced from the same stimuli <br />How is this defined? <br />Receptor <br />Integration center <br />An effector <br /> <br />The response <br />The neural reflex involves sensory fibers to CNS and motor fibers to effectors <br />Reflex arc: composition <br />Wiring of a neural reflex <br />Five steps <br />Arrival of stimulus and activation of receptor <br />Activation of sensory neuron <br />Information processing <br />Activation of motor neuron <br />Response by an effector <br />Step 1: the arrival of a stimulus and activation on a receptor <br />The receptor must be either a specialized cell or the dendrites of a a sensory neuron <br />These receptors are sensitive to physical or chemical changes in the body or the external environment <br /> <br />Step2: Activation of a sensory neuron <br />Stimulation of pain receptors leads to the formation of propagation of an action potential along the axons of the sensory neurons <br />The information reaches the spinal cord via the dorsal root <br />Step 3: Information processing <br />This stage begins when there is a release of neurotransmitters from the synaptic bulb and arrive at the postsynaptic membrane of the interneuron <br />This results in an EPSP which is integrated with other stimuli arriving at the postsynaptic neuron <br />Step 4: activation of a motor neuron <br />Once the information is received, motor neurons carry action potentials through the ventral root of the spinal nerve <br /> <br />Step 5: response of a peripheral receptor <br />The action potential causes a release of neurotransmitters in the synaptic cleft which leads to a response by a peripheral receptor <br />This pull back reflex form something hot is typically described as being negative feedback because it is protective <br />Figure 13.16 Components of a Reflex Arc <br />Reflex classification <br />According to <br />development <br />Site of information processing <br />Nature of resulting motor response <br />Complexity of neural circuit <br />Figure 13.17 Methods of Classifying Reflexes <br />reflex classifications: innate <br />Result from connections that form between neurons during development <br />Acquired reflexes <br />Learned, and typically more complex <br />Acquired <br />Acquired reflexes <br />Learned, and typically more complex <br /> <br />More reflex classifications <br />Cranial reflexes <br />Reflexes processed in the brain <br />Spinal reflexes <br />Interconnections and processing events occur in the spinal cord <br />still more reflex classifications: somatic <br />Involuntary control of the muscular <br />Might need to be immediate, rapid response <br />Can also be voluntary <br />Non precise reflexes <br />Types: <br />Superficial reflexes are triggered on the skin <br />Stretch reflexes triggered by the elongation of a tendon <br />Also called myotactic reflexes <br />Visceral <br />Visceral reflexes (autonomic reflexes) <br />Control activities of other systems <br /> <br />and more reflex classifications <br />Monosynaptic reflex <br />Sensory neuron synapses directly on a motor neuron <br />Typical of a transmission of a chemical response <br />Common also for stretch reflex <br />No interneuron involved <br />Polysynaptic reflex <br />Composition: <br />At least one interneuron between sensory afferent and motor efferent <br />Longer delay between stimulus and response depending on how many synaptic junction made <br />Produce more complicated response <br />Control several muscle groups <br />Figure 13.18 Neural Organization and Simple Reflexes <br />SECTION 13-5 Spinal Reflexes <br />Types <br />They have a large range of types: <br />Some are monosynaptic reflexes involving a single segment of the spinal cord <br />Other involve the many segments <br />The most complicated type is described as being intersegmental reflex arcs <br />Spinal Reflexes <br />Range from simple monosynaptic to complex polysynaptic and intersegmental <br />Many segments interact to form complex response <br />Monosynaptic Reflexes <br />Stretch reflex automatically monitors and regulates the skeletal muscle length and tone <br />Typical A type Fibers (move the fastest) <br /> <br />Figure 13.20 The Patellar Reflex <br />Patellar reflex <br />Patellar (knee jerk) reflex <br />Sensory receptors are muscle spindles that activated when they are stretched <br />This is the result of the tap on the patellar ligament’s special sensors which cause the stretch of muscle spindles of the quadriceps group <br />This causes a rapid increase in muscle tone <br />A rapid decrease in the sensory information then allows the muscle recover to less muscle tone <br />Figure 13.19 Components of the Stretch Reflex <br />What are muscle spindles? <br />These are the sensory receptors which are involved in the stretch reflex <br />There are two parts to each muscle spindle <br />Intrafusal muscle fibers <br />Extrafusal muscle fibers <br />These are responsible for maintaining muscle tone <br />Figure 13.21 Intrafusal Fibers <br />Intrafusal fibers <br />Innervated by both sensory and motor neurons <br />Dendrites of the sensory neuron surround the central portion of the intrafusal fibers <br />Axons from the spinal nerve form neuromuscular junctions at the end of this fiber <br />Innervated by motor neurons called gamma motor neurons and their axons are called gamma effectors <br />Polysynaptic reflexes <br />Produce more complicated responses <br />Can include those of ESPS and ISPA at CNS motor nuclei may include the inhibition or the stimulation <br />Tendon reflex <br />Withdrawal reflexes <br />Flexor reflex <br />Crossed extensor reflex <br />Tendon reflex <br />Since the stretch reflex monitors the length of the skeletal muscle <br />Then the tendon reflex monitors the external tension produced during a muscular contraction and prevents the tearing or breaking of the tendons <br />This requires sensory receptors which are distinct from those of the muscle spindles and the proprioceptors in the tendons <br />Thus as the tension increase on a skeletal muscle, increased inhibitory response occurs to prevent the tearing of the muscle <br /> <br />Withdrawal Reflexes <br />A reflex which moves an affected part of the body from the source of stimulation <br />Typically initiated by pain stimulation <br />Two types: <br />Flexor reflexes <br />Reciprocal inhibition <br />Cross Extensor Reflexes <br />Flexor reflex <br />Affects muscles of the limb <br />Respond to pain when you step on a tack <br />Here the sensory neurons affect interneurons which in turn affect the motor neurons <br />Reciprocal Inhibition <br />This means that when one set of muscles contract another set must relax <br />This means that when flexors contract, extensors relax <br />This response is more complicated than a monosynaptic response <br />If the stimuli is strong, many muscle groups can be affected <br />The effects are longer lasting the that of the patellar response <br />Crossed Extensor Reflexes <br />We know that the stretch, tendon, and withdrawal reflexes are called ipsilateral reflex arcs meaning that sensory and motor response occurs on the same side of the body <br />Those that occur on the opposite side of the body are called crossed extensor reflex arcs also known as contraleteral reflex arc <br />There are five types <br /> <br />Polysynaptic reflexes <br />Involve pools of interneurons <br />Are intersegmental in distribution <br />Involve reciprocal inhibition <br />Have reverberating circuits to prolong the motor response <br />Several reflexes may cooperate to produce a coordinated response <br />The five types of crossed extensor reflex <br />Those involving pools of interneurons <br />Intersegmental in distribution <br />Involve reciprocal inhibition <br />Reverberating circuits <br />Coordinated control response <br />Pools of interneurons <br />Processing occurs in pools of interneurons <br />The result might be excitation or inhibition of motor neurons <br />the flexor and crossed extensor reflexes direct specific muscle contractions <br />Segmental distribution <br />These interneuron pools are found in segmental groups and may activate muscle groups in many parts of the body <br />Affecting a plexus <br /> <br /> <br />An activity which coordinates muscle contractions and reduces resistance to movement <br />In the flexor and crossed extensor reflexes <br />Reverberating circuits <br />Positive feedback between interneurons that innervate motor neurons and the processing pool maintains the stimulation even after the stimulus has faded <br />Coordinated Control response <br />This is the ability to coordinate the response of activating one muscle group and inhibiting the other for an action to occur <br />Figure 13.22 The Flexor and Crossed Extensor Reflexes <br />SECTION 13-6 Integration and Control of Spinal Reflexes <br />Reflex behaviors can occur automatically <br /> <br />General <br />Reflex motor behaviors occur automatically without instructions from higher centers <br />However, descending tracts from higher centers acting through interneurons can inhibit of stimulate a reflex response <br />Voluntary movements and reflex patterns <br />We known that there are certain reflex patterns existing in the spinal cord <br />However, higher centers can control these as well <br />This means that fewer descending tracts are required for there control <br />and these provide the finer control <br />An important example is the biceps brachii muscle triceps brachii <br />Control of the spinal reflexes <br />Brain can facilitate or inhibit motor patterns based in spinal cord <br />Motor control involves a series of interacting levels <br />Monosynaptic reflexes are the lowest level <br />Brain centers that modulate or build on motor patterns are the highest <br />Reinforcement and inhibition <br />A single EPSP may depolarize the postsynaptic neuron sufficient to generate an action potential but can make the neuron more sensitive to other ESPS <br />ISPS will make make a postsynaptic neuron less sensitive to a response, this is a process of reenforcement <br />Reinforcement = facilitation that enhances spinal reflexes <br />Spinal reflexes can also be inhibited <br />Babinski reflex replaced by planter reflex in an adult <br />Babinski reflex: types <br />Positive: fanning of the toes in an infant <br />Negative: no fanning of toes in the adult <br />Figure 13.23 The Babinski Reflexes <br />You should now be familiar with: <br />The structure and functions of the spinal cord. <br />The three meningeal layers that surround the CNS. <br />The major components of a spinal nerve and their distribution in relation to their regions of innervation. <br />The significance of neuronal pools. <br />The steps in a neural reflex. <br />How reflexes interact to produce complicated behaviors. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109519688836958612?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095196356935436872004-09-14T14:08:00.000-07:002004-09-14T14:12:36.936-07:00Chapter 13, part 2 <br />The Spinal Cord and Spinal Nerves <br />SECTION 13-3 Spinal Nerves <br />31 pairs of spinal nerves <br />Nerves consist three coverings in order: <br />Epineurium <br />Perineurium <br />Endoneurium <br />Epineurium <br />Outermost layer <br />Dense network of collagen fibers <br />Arteries of veins branch through the epineurium and branch within the perinerium <br />Perineurium <br />Middle layer <br />Divides the nerve into a series of compartments <br />Endoneurium <br />Inner most layer <br />Surrounds individual axons <br />Here capillaries which left the perineurium branch <br />Figure 13.8 A Peripheral Nerve <br />Peripheral Nerve Distribution of Spinal Nerves <br />A typical spinal nerve forms lateral to the intervertebral forms where the dorsal and ventral roots unite <br />Ventral root construction <br />Each root contains both sensory and motor neurons <br />Distally the first branch of the spinal nerve contains visceral motor fibers to a sympathetic ganglion <br />This branch has a light color and is called white an is called the white rami <br /> <br /> <br />Sympathetic nerves <br />These are postganglionic fibers that innervate smooth muscle, and organs in the thoracic cavity <br />Gray ramus <br />Unmyleinated fibers <br />They are responsible for innervating glands and smooth muscle in the body wall or limbs <br />Are unmyleinated <br />These rejoin the spinal nerve <br />Dorsal ramus <br />Motor and sensory fibers that innervate the skin and skeletal muscle of the back <br /> <br />Ventral rami <br />Supply the ventrolateral body surfaces on the body wall and the limbs <br /> <br />How communicate? <br />Dorsal, ventral, and white rami also contain sensory fibers <br />Somatic sensory information arrives over the dorsal and ventral rami <br />Visceral sensory information the dorsal root reaches the dorsal, ventral, and white rami <br />Spinal nerves in review <br />White ramus (myelinated axons) <br />Gray ramus (unmyelinated axons that innervate glands and smooth muscle) <br />Dorsal ramus (sensory and motor innervation to the skin and muscles of the back) <br />Ventral ramus (supplying ventrolateral body surface, body wall and limbs) <br />Each pair of nerves monitors one dermatome <br />Figure 13.9 Peripheral Distribution of Spinal Nerves <br />Figure 13.9 Peripheral Distribution of Spinal Nerves <br />What is a dermatome? <br />The region in which a specific region of the skin is monitored by the single pair of spinal nerves <br />Each pair of spinal nerves services its own dermatome <br />Good method of monitoring nervous system damage <br />Figure 13.10 Dermatomes <br />What is a nerve plexus? <br />Complex interwoven network of nerves <br />These are the result of separate ventral rami to provide sensory innervation and motor control to each part of a compound muscle <br />During development small skeletal muscle muscles innervated by different ventral rami fuse together to form large muscles with complex origins, but yet separate ventral rami continue to exists and to supply sensory and motor control to each part of the compd muscle <br />Remember that these spinal nerves form different rami blend together <br />Interwoven network of nerves <br /> <br />Nerve plexus <br />Complex interwoven network of nerves <br />Four large plexuses <br />Cervical plexus <br />Brachial plexus <br />Lumbar plexus <br />Sacral plexus <br />Cervical Plexus <br />Ventral rami of spinal nerves C1 through C5 <br />Innervate muscles of the neck <br />The phrenic nerve is part of this which innervates the diaphram <br />Brachial Plexus <br />Innervates the pectoral girdle and the upper limbs <br />with contributions from the ventral rami of C5 – T 1 <br />Originate from trunks or chords <br />Lumbar plexus <br />Arise from the lumbar segments <br />Innervate the pelvic girdle and lower limbs <br />T12 – L4 <br /> <br /> <br />Sacral Plexus <br />L4 – S4 <br />Sciatic nerve <br />Innervates lower portion of the foot <br />Motor performance <br />Automatic <br />Coordination within the cord <br />Reflexes <br />Stereotyped responses <br />No Conscious ability to control <br />Communication between the brain and spinal cord <br /> <br />Figure 13.11 Peripheral Nerves and Nerve Plexus <br />Figure 13.12 The Brachial Plexus <br />Figure 13.13 The Branchial Plexus <br />Figure 13.13 The Branchial Plexus <br />Figure 13.14 The Lumbar and Sacral Plexuses <br />Figure 13.14 The Lumbar and Sacral Plexuses <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109519635693543687?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095022480230744782004-09-12T13:50:00.000-07:002004-09-12T13:54:40.230-07:00Chapter 13, part 1 <br />The Spinal Cord and Spinal Nerves <br />Learning Objectives <br />Discuss the structure and functions of the spinal cord. <br />Describe the three meningeal layers that surround the CNS. <br />Describe the major components of a spinal nerve and relate their distribution to their regions of innervation. <br />Discuss the significance of neuronal pools. <br />Describe the steps in a neural reflex. <br />Explain how reflexes interact to produce complicated behaviors. <br />SECTION 13-1 General Organization of the Nervous System <br />Divisions of the Nervous System <br />CNS <br />Brain and spinal cord <br />In the white matter, axons arranged in tracts and columns <br />PNS <br />Remainder of nervous tissue <br />In the peripheral nervous system <br />Neuron cell bodies are located in the ganglia <br />Axons are bundled together in nerves with spinal nerves connecting to the spinal cord <br />Cranial nerves connect to the brain <br />In the central nervous system <br />A collection of neuron cell bodies with a common function is called a center <br />A center with a discrete boundary is a nucleus <br />The portions of the brain covered with thick gray matter is called the neural cortex <br />The term higher centers refers to the most complex integrations <br />The white matter <br />The write matter of the CNS contain bundles of axons which share common origins, destinations, and functions <br />These boundaries are called tracts <br />Tracts in the spinal cord are called boundaries <br />Centers and tracts <br />The centers and tracts which link the brain with the rest of the body are called pathways <br />Sensory pathways distribute information from the peripheral receptors to the processing centers in the brain <br />Motor pathways begin at the CNS centers concerned with motor control and end at the effectors which they control <br />Figure 13.1 An Introduction to the Anatomical Organization of the Nervous System <br />SECTION 13-2 Gross Anatomy of the Spinal Cord <br />Gross anatomy continued <br />The adult spinal cord is about 18 inches in length <br />The cord ends between L1 and L2 <br />Posterior surface has a shallow grove called the posterior median fissure <br />The anterior median fissure is the deep grove on the anterior surface <br />Gray matter location <br />The amount of gray matter is the greatest in the segments of the spinal cord which deal with sensory and motor control of the limbs <br />Cervical enlargement: shoulder girdle and upper arms <br />Lumbar enlargement: pelvis and lower limbs <br /> <br />Spinal segments <br />Each spinal segment is associated with a pair of dorsal dorsal root ganglia <br />These ganglia contain the cell bodies of sensory neurons <br />The axons of these cell bodies form the dorsal roots <br />They bring sensor information to the spinal cord <br />Ventral roots <br />Contain the axons of motor neurons that extend into the periphery <br />Control somatic and visceral effectors <br /> <br />Spinal nerves <br />Distal to each dorsal root ganglia, the sensory and motor roots are bound together to create a mixed nerve <br />That is they contain both afferent and efferent fibers <br />Adult spinal cord <br />Localized enlargements provide intervention to limbs <br />31 segments <br />each segment has a pair of dorsal roots and a pair of ventral roots <br />Filum terminale <br />Conus medularis <br />Spinal nerves extend off cord to form mixed nerves <br />Mixed nerves <br />How locate <br />Each identified by their association with a adjacent vertebrae <br />This is a regional number <br />T1 means that the spinal nerve emerges immediately inferior to vertebra T1 <br />Cervical nerve designation <br />The name comes from the vertebra immediately proceeding it <br />This means that there are 8 cervical nerves <br />Figure 13.3 Gross Anatomy of the Adult Spinal Cord <br />Spinal meninges <br />Provide physical stability and shock absorption, blood vessels branching within these layers deliver oxygen and nutrients to the spinal cord, Three divisions <br />Three layers <br />Dura mater <br />Arachnoid <br />Pia mater <br />Dura mater <br />Outer most layer which covers <br />Composed of dense collagen fibers that are oriented along the longitudinal axis of the cord <br />Tapers to coccygeal ligament <br />Epidural space separates dura mater from walls of vertebral canal and is lined with loose connective tissue, blood vessels, and adipose tissue <br />Figure 13.4 The Spinal Cord and Spinal Meninges <br />Figure 13.4 The Spinal Cord and Spinal Meninges <br />Arachnoid <br />Interior to dura mater are the subdural space, the arachnoid and the subarachnoid space <br />There might not be in real life a subdural space <br />Subarachnoid space contains CSF which acts as a medium for the diffusion of dissolved gases, nutrients, chemical messengers, and waste products <br />Extends inferiorly as far as the fiilum terminale and the dorsal and ventral roots of the cauda equina <br />Pia mater <br />Meshwork of elastin and collagen fibers that are firmly bound to the underlying neural tissue <br />Connective tissue holds the arachnoid and the pia matter together <br />Innermost meningeal layer <br />Denticulate ligaments extend from pia mater to dura mater to hold the layers together <br />There are also dual connections at the foramen magnum and the coccygeal ligaments prevent up and down motion <br />The meningeal membranes are continuous with the connective tissue that surrounds the spinal nerves and the peripheral branches <br />Figure 13.6 The Cervical Spinal Cord <br />Sections through the spinal cord <br />The spinal cord has what is called sectional organization <br />The anterior and posterior fissures mark the divisions between the left and right side of the spinal cord <br />The superficial white matter contains large numbers of of myleinated and unmyleinated axons <br />Gray matter is dominated by cell bodies of neurons, neurogilia, and unmyleinated axons <br />Sectional anatomy of the spinal cord <br />White matter is myelinated and unmyelinated axons <br />Gray matter is cell bodies, unmyelinated axons and neuroglia <br />Projections of gray matter toward outer surface of cord are horns <br />Figure 13.7 The Sectional Organization of the Spinal Cord <br />Figure 13.7 The Sectional Organization of the Spinal Cord <br />Organization of Gray matter <br />Cell bodies of the neurons in the gray matter are organized into functional nuclei <br />Here sensory nuclei relay information from the peripheral nerves <br />Motor nuclei issue commands to the peripheral effectors <br />Describing <br />In section we see that motor and sensory sections are separated from each other <br />Horns of spinal cord <br />Posterior gray horn contains somatic and visceral sensory nuclei <br />Anterior gray horns deal with somatic motor control <br />Lateral gray horns contain visceral motor neurons <br />Gray commissures contain axons that cross from one side of the cord to the other <br />The key is that the different regions have specific motor and sensory nuclei <br />Organization of White matter <br />Divided into six columns (funiculi) containing tracts <br />Ascending tracts relay information from the spinal cord to the brain <br />Descending tracts carry information from the brain to the spinal cord <br />Divisions of the white matter <br />There are three regions of white matter on each side of the column <br />Posterior white: posterior gray horn and posterior median sulcus <br />Anterior white: between the anterior gray horns and the anterior median fissure <br />Lateral white: between the anterior and posterior columns <br />Responsibility <br />Each column contains a tract <br />A bundle of axons in the CNS that uniform in appearance <br />Relay the same type of information in the same direction <br />Divided in two types: <br />Ascending <br />descending <br /> <br />Ascending tracts <br />Carry sensory information toward the brain <br />Descending tracts <br />Carry information away from the brain <br />Convey motor commands <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109502248023074478?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095022203282341532004-09-12T13:45:00.000-07:002004-09-12T14:04:18.620-07:00Nerve impulse <br />These are electrical activities <br />Action potential travels along an axon <br />Information passes from presynaptic neuron to postsynaptic cell in order to be effective <br />Need not be another neuron <br />General properties of synapses: Electrical <br />found in the CNS and PNS <br />Rare <br />Pre- and postsynaptic cells are bound by interlocking membrane proteins linked together called connexons <br />Create protein pores to allow ions to move back and forth <br />Occur in the: <br />Vestibular nuclei of the brain <br />Eye <br />Ciliary ganglia <br />General properties of synapses: chemical <br />More common <br />Excitatory neurotransmitters cause depolarization and promote action potential generation <br />Inhibitory neurotransmitters cause hyperpolarization and <br />suppress action potentials <br />Chemical synapses <br />An arriving action potential may or may not trigger a response <br />Communication may occurs in only one direction <br /> <br />Classification of neurotransmitters <br />Excitatory <br />Inhibitory <br />However may not be exclusive <br />ACH is both <br />Cholinergic synapses <br />Release acetylcholine (ACh) <br />Information flows across synaptic cleft <br />Synaptic delay occurs as calcium influx and neurotransmitter release take appreciable amounts of time <br />ACh broken down <br />Choline reabsorbed by presynaptic neurons and recycled <br />Synaptic fatigue occurs when stores of ACh are exhausted <br />Synaptic delay <br />The time between the arrival of the neurotransmitter and the effect on the postsynaptic membrane <br />The diffusion time is a small part of the entire process <br />Most of it is due to the calcium influx and the neurotransmitter release time <br /> <br />Synaptic fatigue <br />Under conditions of constant stimulation, the recovery time to make more ACH is delayed <br />When the levels of ACH are restored then, communication can occur once again <br /> <br />Figure 12.19 The Function of a Cholinergic Synapse <br />Figure 12.19 The Function of a Cholinergic Synapse <br />Other neurotransmitters <br />Adrenergic synapses release norepinephrine (NE) <br />Other important neurotransmitters include <br />Dopamine <br />Serotonin <br />GABA (gamma aminobutyric acid) <br />Dopamine <br />CNS neurotransmitter <br />Lack of may cause Parkinson’s disease <br /> <br /> <br />Serotonin <br />CNS <br />Lack of may cause depression <br /> <br />Gamma aminobutyric acid <br />Reduce the effects of anxiety <br /> <br />Neuromodulators <br />Influence post-synaptic cells response to neurotransmitter <br />Neurotransmitters can have direct or indirect effect on membrane potential <br />Can exert influence via lipid-soluble gases <br />Figure 12.21 Neurotransmitter Functions <br />Figure 12.21 Neurotransmitter Functions <br />Figure 12.21 Neurotransmitter Functions <br />Neuromodulators <br />Compds that have a direct effect on membrane potential <br />Compds that have an indirect effect on membrane potential <br />Lipid soluble gases that exert their effects inside of the cell <br /> <br />Direct effect <br />Open and close ion channels <br />ACH <br />ionotropic <br /> <br />Indirect effect <br />Work through secondary messengers <br />metabotropic <br /> <br />Lipid soluble gases <br />NO <br />CO <br />Work through secondary messengers <br />Neuromodulators <br />These alter the response by changing the presynaptic neuron or the postsynaptuc neurons response to the neurotransmitter <br />Typically protein in nature <br />Properties of neuromodulators <br />Long term effects which are slow to appear <br />Trigger responses that involve intermediary compds <br />May affect both pre and post neurons <br />Can be release alone or in concert with neurotransmitters <br />Sometimes a neurotransmitter can be a neuromoedulator at a different receptor site <br />Opioids <br />Endorphins: similar to opium effects <br />Enkephalins: <br />Endomorphins <br />dynorphins <br />SECTION 12-6 Information Processing <br />Information processing <br />Simplest level of information processing occurs at the cellular level <br />Excitatory and inhibitory potentials are integrated through interactions between postsynaptic potentials <br />Excitatory postsynaptic potential <br />Graded depolarization <br />Result of the opening and closing of chemically regulated membrane channels <br /> <br /> <br />Inhibitory postsynaptic potential <br />Graded hperpolarization <br />Works on chemically channels <br /> <br />Postsynaptic potentials <br />EPSP (excitatory postsynaptic potential) = depolarization <br />EPSP can combine through summation: two types <br />Temporal summation <br />Spatial summation <br />IPSP (inhibitory postsynaptic potential) = hyperpolarization <br />Most important determinants of neural activity are EPSP / IPSP interactions ratios <br />Figure 12.22 Temporal and Spatial Summation <br />Figure 12.22 Temporal and Spatial Summation <br />Figure 12.23 EPSP – IPSP Interactions <br />Presynaptic inhibition <br />GABA release at axoaxonal synapse inhibits opening calcium channels in synaptic knob <br />Reduces amount of neurotransmitter released when action potential arrives <br />Temporal summation <br />Additional stimuli arriving <br />Occurs in rapid success <br />This means that more chemically regulated channels open from this stimuli <br />The degree of depolarization then increases <br /> <br />Spatial summation <br />Multiple stimuli arrive and enhance the effect <br />The effects are cumulative <br />Figure 12.24 Presynaptic Inhibition and Facilitation <br />Presynaptic facilitation <br />Activity at axoaxonal synapse increases amount of neurotransmitter released when action potential arrives due to the lowering of the action potential required <br />Enhances and prolongs the effect of the neurotransmitter <br />Figure 12.24 Presynaptic Inhibition and Facilitation <br />Rate of generation of action potentials <br />Neurotransmitters are either excitatory or inhibitory <br />Effect on initial membrane segment reflects an integration of all activity at that time <br />Neuromodulators alter the rate of release of neurotransmitters <br />Rate of generation of action potentials <br />Can be facilitated or inhibited by other extracellular chemicals <br />Effect of presynaptic neuron may be altered by other neurons <br />Degree of depolarization determines frequency of action potential generation <br />You should now be familiar with: <br />The two major divisions of the nervous system and their characteristics. <br />The structures/ functions of a typical neuron. <br />The location and function of neuroglia. <br />How resting potential is created and maintained. <br />You should now be familiar with: <br />The events in the generation and propagation of an action potential. <br />The structure / function of a synapse. <br />The major types of neurotransmitters and neuromodulators. <br />The processing of information in neural tissue. <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109502220328234153?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1095021898427163822004-09-12T13:44:00.000-07:002004-09-12T13:44:58.426-07:00Learning Objectives <br />Describe the two major divisions of the nervous system and their characteristics. <br />Identify the structures/functions of a typical neuron. <br />Describe the location and function of neuroglia. <br />Explain how resting potential is created and maintained. <br />Describe the events in the generation and propagation of an action potential. <br />Learning Objectives <br />Define the structure/function of a synapse. <br />List the major types of neurotransmitters and neuromodulators. <br />Explain the processing of information in neural tissue. <br />SECTION 12-1 An Overview of the Nervous System <br />nervous system overview <br />Nervous system <br />Provides swift, brief responses to stimuli <br />Endocrine system <br />Adjusts metabolic operations and directs long-term changes <br />Nervous system includes <br />All the neural tissue of the body <br />Basic unit = neuron <br />Divisions of the Nervous system <br />CNS (Central Nervous system) <br />Brain and spinal cord <br />PNS (Peripheral Nervous system) <br />Neural tissue outside CNS <br />Afferent division brings sensory information from receptors <br />Efferent division carries motor commands to effectors <br />Efferent division includes somatic nervous system and autonomic nervous system <br />Somatic Nervous system <br />Controls skeletal muscle <br />Most causes is under voluntary control <br />In the case of a reflex, is not under conscious control <br />Autonomic nervous system <br />Called visceral motor system <br />Provides automatic regulation of smooth, cardiac muscle and grandular secretions at the subconscious level <br />ANS includes the sympathetic and parasymapthetic divisions <br />These are antagonist to each other <br />Figure 12.1 Functional Overview of the Nervous System <br />SECTION 12-2 Neurons <br />Neuron structure <br />Perikaryon <br />Neurofilaments, neurotubules, neurofibrils <br />Axon hillock <br />Soma; cell body <br />Axon <br />Collaterals with telodendria <br />Figure 12.2 The Anatomy of a Multipolar Neuron <br />Synapse <br />Site of intercellular communication <br />Neurotransmitters released from synaptic knob of presynaptic neuron <br />Figure 12.3 The Structure of a Typical Synpase <br />Neuron classification <br />Anatomical <br />Anaxonic <br />Unipolar <br />Bipolar <br />Multipolar <br />Anaxonic <br />Small and have no features which distinguish axons from dendrites <br />Located in the brain and organs of special sense <br />Bipolar Neurons <br />Two process, one axon and one dendrite <br />Occur in organs of special sense <br />Unipolar neurons <br />Dendrites and axons are continuous <br />Most sensory neurons of the PNS <br />Multipolar Neurons <br />Two of more dendrites <br />Single axon <br />Typically motor neurons <br />Figure 12.4 A Structural Classification of Neurons <br />Functional <br />Sensory neurons <br />deliver information from exteroceptors, interoceptors, or proprioceptors <br />Motor neurons <br />Form the efferent division of the PNS <br />Interneurons (association neurons) <br />Located entirely within the CNS <br />Distribute sensory input and coordinate motor output <br />Exteroceptors <br />Provide information about the external environment in the form of: <br />Touch <br />Temperature <br />Pressure sensations <br />Smell <br />Sight <br />Hearing <br />Proprioceptors <br />Monitors the position and movement of the skeletal muscle <br />Interoceptors <br />Monitors the digestive, respiratory, cardiovascular, urinary, and reproductive systems and provides sensations taste, deep pressure, and pain <br />Motor neurons <br />Efferent neurons <br />Efferent division of the PNS <br />Carry information away from the CNS to an peripheral effector in a peripheral tissue <br />Two types of motor neurons <br />Somatic motor neurons <br />Visceral motor neurons <br />Somatic Motor Neurons <br />SNS = somatic nervous system <br />Innervates skeletal muscle <br />Visceral Motor Neuron <br />ANS <br />Innervates smooth and cardiac muscle, glands, and adipose tissue <br />The order of connection: <br />Preganglionic fibers <br />Autonomic ganglia <br />Post ganglia fibers <br />Interneurons <br />Figure 12.5 A Functional Classification of Neurons <br />SECTION 12-3 Neuroglia <br />Neuroglia of the Central Nervous System <br />Four types of neuroglia in the CNS <br />Ependymal cells <br />Related to cerebrospinal fluid <br />Astrocytes <br />Largest and most numerous <br />Oligodendrocytes <br />Myelination of CNS axons <br />Microglia <br />Phagocytic cells <br />Interneurons <br />Association <br />Found in brain and spinal cord <br />Responsible for the distribution of sensory information <br />Also responsible for the distribution of motor activity <br />Figure 12.6 An Introduction to Neuroglia <br />Figure 12.7 Neuroglia in the CNS <br />Figure 12.7 Neuroglia in the CNS <br />Organization <br />The organization of the CMS differs from the PNS because of the greater number of distinctive cell types <br />Ependymal cells <br />The ventricles and the central canal are lined with these cells <br />They are responsible for the production of CSF <br />Typically cuboidal to columnar in shape <br />These are cilia covered cells which helps the CSF move through the ventricles and the central canal <br />Astrocytes <br />Largest and most numerous of the cell types <br />Jobs functions: <br />Maintaining the blood brain barrier <br />Create a network for the CNS <br />Repair damaged neural tissue <br />Guiding neuron development <br />Controlling the interstital environment <br />Maintaining the Blood brain barrier <br />The neurons must be isolated from the changes that occur in the blood <br />These cells isolate the neurons from the rest of circulation <br />They are designed to form a blanket around the blood capillaries <br />CNS Framework <br />The neuron network builds upon the Astrocytes <br />Repair of damaged nerve tissue <br />These cells help stabilize the tissue and prevents more damage <br />Guiding neuron development <br />Directs the growth and interconnections of neurons <br /> <br />Controlling the interstital environment <br />Adjusts the composition of interstital fluid <br />Regulates the concentration of potassium and sodium ions and carbon dioxide levels <br />Provide a means for the movement of ions and nutrients between the capillaries and the neurons <br />Absorb and recycle neurotransmitters <br />Release chemical which can enhance or suppress communication between the neurons <br />Oligodendrocytes <br />Smaller than and with fewer cell process than astrocytes <br />Responsible for wrapping around an axon with concentric mylein layers <br />Often wraps around several axons <br />Allows neuronal tissue to appear white in color <br />Unmyleinated nerve tissue is gray in color <br />Microglia <br />Smallest and least numerous of the cells of the CNS <br />Migrate through neural tissue <br />Wandering police force <br />Neuroglia of the Peripheral Nervous System <br />Two types of neuroglia in the PNS <br />Satellite cells <br />Surround neuron cell bodies within ganglia <br />Schwann cells <br />Ensheath axons in the PNS <br />Only one axon <br />However, many are required for that one axon <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109502189842716382?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1090067548859207382004-07-17T05:31:00.000-07:002004-07-17T05:32:28.860-07:00&nbsp;&nbsp; <br />&nbsp;&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />_____ 1.&nbsp; Given the following AA, the carbon labeled with the number _______is&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;alpha carbon. <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____ 2.&nbsp; This amino acid classification is <br />&nbsp; <br />a.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; basic <br />b.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; non polar <br />c.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; acidic <br />d.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; neutral and polar <br />&nbsp; <br />&nbsp; <br />_____ 3.&nbsp; A protein with a positive lead acetate test could indicate the <br />&nbsp;&nbsp;&nbsp; the presence of&nbsp; _____________ <br />&nbsp; <br />_____ 4.&nbsp; Nitrous Acid Test, tests for the presence of an amino nitrogen, and <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; the bubbles that are produced represent which gas <br />&nbsp; <br />_____ 5.&nbsp; Ninhydrin would give a negative for what compd classes <br />&nbsp; <br />_____ 6.&nbsp; The&nbsp; _______ test determines the presence of a phenol in the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; following: <br />&nbsp; <br />_____ 7.&nbsp; The Benedicts’ test determines the presence of a reducing sugar for <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; what carbohydrates <br />&nbsp; <br />_____ 8.&nbsp; Tannic acid will _____ pancreatin.&nbsp; Proof can be shown by testing <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; starch with IKI and getting a&nbsp; ______ color . <br />&nbsp; <br />_____ 9.&nbsp; Given the cyclic monosaccharide below, what is its origin <br />that is it form a aldose or a ketose. <br />&nbsp; <br />____ 10. In determining the activity of pancreatin on starch with the _____&nbsp;&nbsp;&nbsp; <br />test, brown indicates that the enzyme is active and converting the starch to glucose. <br />&nbsp; <br />_____ 11. Given [enzyme] = constant and is unsaturated; increasing the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; concentration of the substrate will have a _____ effect on the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; turnover number, that is the turnover number will continue to _____ <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; until the enzyme is fully saturated, and then the turnover can not <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; increase any more. <br />&nbsp; <br />_____ 12. _____ and _____&nbsp; would be an appropriate enzyme and substrate &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;combination or couple.&nbsp; The tip off to enzyme activity is the presence <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; of a pink colour when the soln is tested with phenolphthalein. <br />&nbsp; <br />_____ 13.&nbsp;&nbsp; Given a human enzyme which is saturated, you start at 0 deg C and <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; increase the temperature to 100 deg C.&nbsp; The turn over number will? <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />_____ 14. The temperature _____ oC will not denature a human enzyme with an opt. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; Of 0 deg C <br />_____ 15. The nitrogenous base&nbsp; _____&nbsp; is found in RNA only. <br />&nbsp; <br />_____ 16.&nbsp; _____ are designed to ferry individual AAs to the ribosomes for &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; protein synthesis. <br />&nbsp; <br />_____ 17. Enzymes which are made up of many peptide bonds, would test positive <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; for the&nbsp; _____ test; the test for complexity. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />_____ 18. Enzymes which are frequently protein like in nature, can be natured <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;by the factors that denature any protein, and upon denaturing, the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; enzyme turnover number will ______. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____ 19. All carbohydrates have _____ rotations, which can be used to <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; identify them. <br />&nbsp; <br />&nbsp; <br />_____ 20. Breaking the peptide bonds of the primary AA sequence of a protein is <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; called ______. <br />&nbsp; <br />_____ 21. Given the following formula: <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; specific rotation&nbsp; =&nbsp;&nbsp;&nbsp; observed rotation <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; cell length x concentration <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp; <br />_____ 22. Which one of the structures below lack a hemiacetal structure so that <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; the carbohydrate can not react with Benedict’s soln. <br />&nbsp; <br />&nbsp; <br />_____ 23. Which of the following would be a proper set of RNA - RNA base pair &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;relationships: <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />____ 24. Which of the following statements is false about all nucleic acids. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />______ 25. In the general class of a ribonucleotide. which is absent. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />______ 26. Which of the following could not possibly be a codon in mRNA. <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____&nbsp; 27. Examine of the following DNA strands.&nbsp; This would represent what kind <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; of change. The cause and effect relationship <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;original ===> C-U-G-A-U-G-C-A-A-U-C <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;mutated&nbsp; ===> C-U-G-U-G-C-A-A-U-C- <br />&nbsp; <br />_____&nbsp; 28. Which one of the following sample mixtures would have the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; highest proportion of saturated compounds according to the I index. <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____&nbsp; 29. Given the following Iodine numbers, which one of the following <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; sample mixtures would have the lowest m.p. <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____ 30.&nbsp;&nbsp; Which one of the following statements about lipids (any type) is <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; false. <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____ 31. Which one of the properties of Tags <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />_____ 32.&nbsp;&nbsp; If 4.2 grams of bromine is used to completely react with 0.4 grams &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; of a lipid, the approximate Iodine number would be: <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Iodine number = (grams of Bromine - .2) x 8.0 <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; grams of fat. <br />&nbsp; <br />&nbsp; <br />______ 33.&nbsp; Sometimes an unusual base inosine is found on the_____ position of <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; the tRNA anticodon. <br />&nbsp; <br />&nbsp; <br />______ 34.&nbsp; mRNA is made directly off the _____ with Crick Watson base paring <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />______ 35.&nbsp; The _____ of a large block of deoxyribonucleotides on the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; informational strand would _____ the primary amino acid <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; sequence of a translated protein <br />&nbsp; <br />&nbsp; <br />______ 36.&nbsp; Given the monosaccharide fructose, the _____ test is specific <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;for the presence of this ketohexose. <br />&nbsp; <br />&nbsp; <br />______ 37.&nbsp; You are given the following two carbohydrates: galactose and <br />sucrose.&nbsp; You test the solutions with Benedict’s soln.&nbsp; Benedict’s&nbsp;&nbsp;&nbsp;&nbsp; soln. will test. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />______ 38.&nbsp; You are told that the deoxyribonucleotide of A in a DNA <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; information strand has been replaced with a C.&nbsp; This would be base <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; substitution and will _______ change the primary amino acid <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; sequence. <br />&nbsp; <br />&nbsp; <br />______39.&nbsp;&nbsp; The _____tests would be a good test to distinguish starch from <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; galactose. <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp;_____ 40. Given the following modified dipeptide:&nbsp; Which test/s would be <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; positive: <br />&nbsp; <br />_____ 41.&nbsp;&nbsp; Given a normal strand of DNA and a mutated strand, what amino acid replaces that amino acid of the mutated strand replaces that of the normal strand. <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Normal&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Mutated <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; DNA&nbsp;&nbsp; A-T-T-G-G-C-C-T-A&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; M A-C-T-G-G-C-C-T-A <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />_____ 42.&nbsp;&nbsp; On the ribosome following initiation during protein synthesis, the&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; t-RNA bearing the new incoming amino acid pairs with the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; condon on the p position on the ribosome. <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />_____ 43.&nbsp;&nbsp; Given the formula for the I index with the following data: <br />Determine the quantity of lipid present and the quantity of bromine added. This Iodine would be define this lipid as being an oil.&nbsp; <br />Hint:&nbsp; calculate the Iodine number. <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Iodine number = (grams of Br2 – 0.2) X&nbsp; 8.0 <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Grams of lipid <br />&nbsp; <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; Flask and cork weight) <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Empty&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; with&nbsp; &nbsp;&nbsp; (g lipid)&nbsp; with&nbsp;&nbsp;&nbsp; with&nbsp;&nbsp; (g bromine) <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; lipid&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (CH2Cl2) Br2 <br />&nbsp; <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 35.00&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 35.4&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 40.1&nbsp;&nbsp; 44.0 <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />_____ 44. Given the monosaccharide glucose, the measured specific rotation <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; is an equilibrium balance between the Œ and õ anomeric forms of that <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; carbohydrate in solution. <br />&nbsp; <br />______ 45.&nbsp; Carbohydrates which are common in biological systems are the D in <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; configuration. <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />_____ 46.&nbsp;&nbsp; Given the following information strand of DNA, the protein <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; represented below would be the appropriate sequence: <br />&nbsp; <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; informational strand&nbsp; C-C-T-G-A-C-G-C-G-G-T-T <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The protein is:&nbsp; Met-Pro-Asp-Ala-Val <br />&nbsp; <br />_____ 47.&nbsp;&nbsp; The anti-codon for C-C-U: is G-G-A <br />&nbsp; <br />_____48.&nbsp;&nbsp;&nbsp; All final proteins start with the amino acid methionine. <br />&nbsp; <br />_____ 49.&nbsp;&nbsp; An error or a mutation in RNA can be copied into DNA and passed <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; on to future generations. <br />&nbsp; <br />_____ 50.&nbsp;&nbsp; Is the following information as presented correct?&nbsp; Is this the <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; dipeptide, informational strand, and template configuration? <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Information strand&nbsp; (5’è 3’)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; T-A-C-C-G-A <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Template strand&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (3’è5’)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; A-T-G-G-C-T <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; m-RNA &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp; <br />(5’è3’)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; U-A-C-C-G-A <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Dipeptide&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Try-Arg <br />&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />&nbsp; <br />As the late Jim Morrison said:&nbsp; “what have they done to my fair city?”&nbsp; <br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br />&nbsp;&nbsp; <br />&nbsp;&nbsp; <br />&nbsp;&nbsp; <br />&nbsp;&nbsp; <br />&nbsp;&nbsp; <br />&nbsp; <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-109006754885920738?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1089842189027590422004-07-14T14:56:00.000-07:002004-07-14T14:56:29.026-07:00 Carbohydrates <br /> <br />Section: 22.1 <br /> <br />• carbohydrates: a member of a large class of naturally occurring polyhydroxy aldehydes or ketones <br /> name of compd. ends w/ the “ose” ending <br /> <br />• monosaccharides: a carbohydrate that can not be broken down into smaller units by hydrolysis with aqueous acid <br />o typically three to seven carbons in length <br /> glucose: pentylhydroxylhexanal <br /> fructose: pentylhydroxylhexanone <br /> galactose: penthylhyroxylhexanal <br /> <br />• disaccharide: a carbohydrate, which yields two monosaccharide on hydrolysis, identical or different. Bonds are really ether like linkages <br />o held together by a glycosidic bond or also called acetal bond <br /> lactose <br /> maltose <br /> sucrose <br /> <br />• polysaccharides: a carbohydrate that is composed of many monosaccharides bonded together. This is really a polymer of many monosaccharides put together end to end. Really a polymer of monosaccharides. Monomer composition or different, and if different order determines the type polysaccharide <br />o complex carbohydrates <br /> glycogen: animal <br /> cellulose: plant <br /> amylose: plant <br /> amylopectin: plant <br /> <br /> <br />• aldose: monosaccharide which contains an aldehyde functional group <br /> <br />• ketose: a monosaccharide which contains a ketone functional group <br /> <br /> <br />Naming and Examples of monosaccharides <br /> <br />• the number of carbons is specified by multiplicative prefixes identical to that in naming other compds <br /> <br />• see page <br /> <br />• can you find the aldehyde functional group? <br /> <br />• can you find the ketone functional group? <br /> <br /> <br /> <br />Section 22.2 Handedness of Carbohydrates <br /> <br />• the simplest of the carbohydrates is the three carbon compd. glyceraldehydes <br />• there exists two forms: <br />o D-glyceraldehyde <br />o L-glyceraldehyde <br />• these compds exist chiral character <br />o meaning lack of plane of symmetry <br />o they are mirror images of each other <br />o same chemical properties <br />o all physical properties are the same except their ability to rotate a plane of polarized light <br />o there are called optical isomers <br />o the measurement of optical rotations is accomplished by a device called a polarimeter <br />o one will rotate light to the right and the other will rotate light to the left <br />o this compd. w/ one chiral center can only have two optical isomers <br />o if there are more chiral centers, then there are more optical isomers possibilities <br />o if you have 2 chiral centers, then you can have four optical isomers <br /> two optical isomer pairs <br />o thus there is a D and L erythrose and a D and L threose <br />o however, erythrose and threose are stereoisomerisms <br /> stereoisomers: some formula and connections but different spatial arrangement <br /> diastereomers: stereoisomers that non mirror images of each other <br /> <br />Section 22.3 Fisher Projections <br /> <br />D-sugars: monosaccharides with the OH group on the chiral atom farthest from the carbonyl group pointing to the right in a <br /> <br />Fisher projection. The representation “dextro” is derived from the fact that the OH group points to the right <br /> <br />L-sugar: monosaccharide with the OH group on the chiral atom farthest from the carbonyl group pointing to the left in a Fisher projection. The representation “levo” is derived from the fact the OH group points to the left <br /> <br /> <br />• see page 603 <br /> <br />In a Fisher projection, the carbonyl group of the ketone or the aldehyde is always placed at the top of the projection <br /> <br />glyceraldehyde is the simplest of the monosaccharides <br /> <br /> this means that the OH and the H groups pointing to the left and the <br /> right of the chiral atoms are projecting into the paper and those above <br /> and below the chiral centers are projecting out of the paper <br /> <br /> see page 603 again <br /> <br /> note in the D sugar form the OH group projects out of the paper <br /> and to the right <br /> note in the L sugar form the OH group projects out of the paper and <br /> to the left <br /> <br /> see examples page 606 <br /> <br /> <br /> <br />22.4 Structure of Glucose and others <br /> <br />• sometimes call dextrose or blood sugar <br />• source of energy for almost all living organisms <br />• stored as a polymer as starch in plants and glycogen in animals <br />• hemiacetal forms from the internal condensation of an aldehyde group and an alcohol group of that sugar <br />• internal hemiacetal formation is possible <br />• the C1 and C5 carbons condense to form a six member ring which has an oxygen in the ring instead of a carbon <br />• see figure 22.3 page 608 <br />• OH groups pointing left point up in the cyclic structure and those which point to the right, point down <br />• the hemiacetal carbon is always bonded to two oxygen atoms <br />• this means that the carbon is chiral <br />• this creates alpha and beta anomers <br />• in the beta form the OH group points up and in the alpha form the OH group points down <br />• anomers: cyclic sugars that differ only in the positions of the on the hemiacetal carbon; the alpha form has the OH group on the opposite side of the –CH2OH; the beta form has the –OH group on the same side as the –CH2OH <br />• anomeric carbon: the hemiacetal C atom in the cyclic sugar, the C atom bonded to an –OH group and an O in the ring <br />• mutarotation: change in rotation of plane polarized light resulting form the equilibrium between cyclic anomers and the open chain form of a sugar <br />• see page 609 for review: KNOW! <br /> <br /> <br />Section 22.5: Important Monosaccharides <br /> <br />• the monosaccharides w/ their many hydroxyl groups which permit hydrogen bonding between other monosaccharides are generally high melting, white crystalline solids <br />• w/ many opportunities for hydrogen bonding, they have high solubility in water and are insoluble in non-polar solvents <br />• most are sweet in taste and digestible as an energy source <br />• those of interest include: <br />o glyceraldehyde <br />o fructose <br />o aldohexoses <br />o aldopentoses <br />• most are in the D-family <br />• Glucose: <br />o most important of the carbohydrate of human metabolism <br />o final product of carbohydrate digestion <br />o provides acetyl groups for the Krebs’ Cycle <br />o hormones insulin and glucagon maintain proper glucose levels in the blood <br />• Galactose: <br />o component of the digestion of lactose <br />o aldohexose (see page 612) <br />o identical in arrangement of the carbons and hydroxyl groups in order, but orientation of the OH- group at position turned and opposed to glucose where it is turned down <br />o the body converts galactose to glucose <br />o galactose can be made from glucose to provide lactose for breast milk <br />o galactosemia: genetic disorder which the individual cannot process galactose, its build up may cause mental retardation, liver failure, and cataracts <br /> <br /> <br />• Fructose: <br />o see page 613 <br />o ketohexose <br />o part of the glycolysis cycle <br />o six carbon sugar <br />o because of the presence of the ketone functional group and through internal condensation with carbon # 5, a five member ring results <br />o there are also α and β anomers <br />o sweeter then sucrose <br /> <br />• Ribose and 2-Deoxyribose <br />o see page 613 <br />o both are five carbon aldehyde sugars <br />o found in many aspects of biological chemistry, especially DNA, RNA, and cyclic AMP <br /> <br />22.6 Reactions of Monosaccharide <br /> <br />• Reactions w/ oxidizing agents: Reducing sugars by definition <br />o aldehydes can be oxidized to carboxylic acids, but that reaction applies only to open chained form of the aldose monosaccharides <br />o if you have a given sample, the open chain will continue to react with the oxidizing agent, the equilibrium will shift, until all of the cyclic forms are consumed <br />o any carbohydrate that reacts w/ a reducing agent is called a reducing sugar by definition <br />o a ketose also behave as reducing sugar in basic solution such as Benedicts’ because of a keto-enol tautomeric shift, that is the ketone is converted to an aldehyde <br />o this aldehyde then can undergo oxidation <br />o in basic solns., all monosaccharides of either ketose or aldose origin behave as reducing sugars <br /> <br />• Reactions with Alcohols: <br />o an alcohols is a hemiacetal which can react with other alcohols to make a acetal <br />o a acetal has two OR groups bonded to the same carbon <br />o the class of compounds which reacts when a cyclic hemiacetal reacts together is called a glycoside: <br /> a cyclic acetal formed by the Rx of a monosaccharide with an alcohol w/ accompanied by the release of water, a condensation reaction <br />• the bond which o=is formed by this condensation reaction is called a glycosidic bond, by definition, the anomeric carbon must be involved in that bond <br />• when two monosaccharides are combined, the anomeric carbon of one carbon is reacted w/ the –OH of another monosaccharide <br /> <br />22.7 Disaccharides: <br /> <br />• when you have a disaccharide, the bond can also be α or β <br />• in the example on page 617 there is representation of an α and β bond types. These are stereoisomers of each other <br />• Maltose: <br />o malt sugar <br />o two α D-glucose molecules are linked in an alpha configuration <br />o note that carbons 1 and 4 are involved, hence name is called α 1-4 glycosidic bond <br />• Lactose: <br />o β-D-Galactose <br />o β-D-Glucose <br />o β-1,4 glycosidic bond <br />o age increases risk of lactose intolerance <br /> <br /> <br />• Sucrose: <br />o table sugar <br />o hydrolysis of sucrose produces: <br /> α-D-glucose <br /> β-D-fructose <br />• called invert sugar <br />• non reducing sugar because the anomeric carbons are linked together <br />• bond type is a 1,2 anomeric link <br />• can not ID as α or β link because both anomeric carbons are joined together <br />• only common disaccharide which is not a reducing sugar, a good ID for lab when trying to distinguish between two disaccharides <br /> <br />22.8 Variation on Carbohydrate Theme <br /> <br />• monosaccharides w/ modified functional groups are found and have many important structural applications, see page 620 <br />• Chitin: <br />o structural polymer <br />o insect shells <br />o N-acetyl-D-glucosoamine <br />• Connective tissue Polysaccharides: <br />o protein fibers are embedded in a matrix of un-branched polysaccharides (mucopolysaccharides) <br />o these gel like polymers behave as lubricants <br />o repeating unit of two modified monosaccharides <br /> Hyaluronate: 25K units in length <br /> rigid material <br /> holds water <br /> synovial fluid <br /> <br /> <br />• Chrondroitin-6-sulfate: <br />o tendons and cartilage <br />o linked to proteins <br />o dietary supplements <br />• Heparin: <br />o another polymer <br />o anticoagulant <br />o various composition contain sulfate groups <br />o has many negative charges to bond tightly to blood clotting factors <br />• Glycoproteins: <br />o a protein that’s a short carbohydrate chain <br />o carbohydrate is connected to the protein by a glycosidic bond between the anomeric carbon and a side chain of the protein, the bond is of two types, a C-N glycosidic bond or C-O glycosidic bond to an oxygen atom of a side chained hydroxyl group <br />o major function is cell surface markers <br />o important in blood group identification <br />o the protein portion is buried in the cell membrane and the carbohydrate portion extends above the surface of the cell membrane <br />o see page 623 <br />o note the common N-acetyl-D-glucose amine bade for all three blood groups <br />o L-fucose is found in all three blood groups <br />o N-acetyl-D-galactose amine is found only in blood group A <br />o D-galactose is found only in blood group B <br />o if you are an AB individual, then you have the separate glycoproteins which contain N-acetyl-galactose amine and galactose as your markers <br /> <br /> <br />22.9 Important Polysaccharides <br /> <br />• Cellulose: <br />o see page 624 <br />o fibrous structure that provides support in plants <br />o made up of β-D-glucose units in repeated fashion <br />o links are called β 1-4 glycosidic bonds <br />o see anti-parallel arrangement <br />o hydrogen bonding holds the structure together <br />o we as humans can not digest cellulose because we lack the enzyme β-cellulase <br /> <br />• Starch: <br />o General properties <br /> polymer of α-D-glucose <br /> joined by α 1-4 glycosidic links <br /> fully digestible because α-amylase <br /> found only in plant material: <br />• beans <br />• potato <br />• wheat <br />• rice <br />o amylose: <br /> 20% of the total plant starch <br /> somewhat soluble in hot water <br /> several hundred to 1000 units of α-D-glucose linked together by α 1-4 glycosidic bonds <br /> coils in helical arrangement, not anti-parallel sheets <br /> w/o branching <br /> <br /> <br />o amylopectin: <br /> 80 % of the starch <br /> identical monomer construction <br /> up to 100,000 monomer units <br /> α 1-6 branch to an α-D-glucose occurs approximately on each 25th α-D-glucose unit, branches can also be 100,000 units long <br /> digested in small intestine by α-amylase which catalyzes the α 1-4 links <br /> <br />o Glycogen: <br /> animal starch <br /> energy storage in the liver and muscles <br /> when used as energy source, the glucose is converted to glucose-6-phosphate for glycolysis <br /> branch points as in amylopectin but every 10 units <br /> size is 1,000,000 units <br /> readily mobilized form of glucose storage <br /> designed to increase the amount of glucose that is immediately available following between meals <br /> important for blood glucose levels and regulation <br /> reservoir of glucose for strenuous muscle activity <br /> the α 1-6 branch is broken down by a debranching enzyme called α 1-6 gluosidase which is found in the liver <br /> other debrancing enzymes, collectively called pancreatins complete the activity in the small intestine <br /> <br /> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108984218902759042?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1089477274636315322004-07-10T09:31:00.000-07:002004-07-10T09:34:34.636-07:00 This is a practice test. summary of similar questions to be found on the final. Does not have every single topic though. <br /> <br /> <br />_____1. What functional group/s could be found in the open chain configuration of a monosaccharide? <br /> <br /> a. hydroxyl <br /> b. aldehyde <br /> c. ketone <br /> d. both aldehyde and ketone groups present at the same time <br /> e. aldehyde or a ketone <br /> <br /> <br />_____ 2. Given the following structure, this sugar represents. <br /> <br /> <br /> <br /> <br /> <br />a. alpha anomer <br />b. beta anomer <br /> c. open chain configuration <br /> d. none of the above <br /> <br /> <br />_____3. The bond, which forms between an UDP-glucose (activated glucose) molecule and glycogen is called a (n) ________ bond. This is the process of adding one glucose molecule to long glycogen chain, adding one glucose molecule at a time. <br /> <br /> a. amine <br /> b. amide <br /> c. peptide <br /> d. alcoholic <br /> e. glycosidic <br /> <br /> <br />_____ 5. The reaction described as being _______ and is called ___________. <br /> <br /> a. condensation; glycolysis <br /> b. condensation; gluconeogenesis <br /> c. condensation; glycogenesis <br /> d. condensation; glycogenolysis <br /> e. condensation; pentose phosphate shunt <br /> a.b. none of the above meet the criteria described <br /> <br />_____ 6. Given that you are of the blood group O, what lipid classification is found on the outer surface of the RBC membrane are responsible for the antigenic response. <br /> <br /> a. phospholipids <br /> b. glycolipids <br /> c. glycoproteins <br /> d. cholesterol <br /> e. none of the above <br /> <br />_____ 7. Amylose (starch) has the following glycosidic links: <br /> <br /> a. alpha 1,4 and alpha 1,6. <br /> b. alpha 1,4 and beta 1,6. <br /> c. beta 1,4 and beta 1,6. <br /> d. beta 1,4 and alpha 1,6. <br /> e. no specific links, all link are random <br /> <br />_____ 8. Hydrolysis of glycogen produces what product/s? <br /> <br /> a. fructose <br /> b. glucose <br /> c. galactose <br /> d. fructose and glucose <br /> e. fructose, glucose, and galactose <br /> <br />_____ 9. An ester of a longed-chained fatty acid and a long chained alcohol falls into what general compd. Classification? <br /> <br /> a. carbohydrate <br /> b. lipid <br /> c. protein <br /> d. oxyacid <br /> e. wax <br /> <br /> <br />_____ 11. CH3-CH=CH-(CH2)16-C-OH represents a __________. <br /> " <br /> O <br /> <br /> a. unsaturated fatty acid <br /> b. saturated fatty acid <br /> c. wax <br />d. triacylglycerol <br /> e. none of the above <br /> <br />For questions 12, 13, 14 consider the following compd. below C=O omitted for simplicity <br /> <br /> H <br /> | <br /> H-C-O-C-(CH2)16-CH=CH-CH3 <br /> | O <br /> H-C-O-C-(CH2)16-CH=CH-CH3 <br /> | O <br /> H-C-O-C-(CH2)16-CH=CH-CH3 <br /> | O <br /> <br /> H <br /> <br />_____ 12. The compd. described above is classified as a ________. <br /> <br /> a. wax <br />b. triacylglycerol (note: alternate name is triacylglyceride) <br /> c. phosphoglyceride <br /> d. sphingolipid <br /> e. steroid <br /> <br />_____ 13. If this compd. were treated with NaOH, the products would be ___________ . <br /> <br />a. glycerol and water <br /> b. glycerol and three fatty acids <br /> c. glycerol and three Na salts of the fatty acids <br /> d. esters and mixture of three Na salts of fatty acids <br /> e. ester and fatty acids <br /> a.b. none of the above <br /> <br /> <br />_____ 14. If I told you that the Iodine number = 20, the compd. is probably <br /> <br /> a. probably solid at RT <br /> b. probably liquid at RT <br />c. can not tell <br /> <br /> <br />_____ 15. Which component is not found in phospholipids? <br /> <br /> a. fatty acids <br /> b. glycerol <br /> c. glucose <br /> d. phosphate <br /> e. all of above <br /> <br />_____ 16. Sphingosine contains __________ . <br /> <br /> a. glycerol <br /> b. two fatty acids <br /> c. phosphate group <br /> d. amino alcohol <br /> e. all of the above <br /> <br /> <br />_____ 17 Mammalian glycolipids do not contain _______________, in their backbone <br /> <br /> a. glycerol <br /> b. sphingosine <br /> c. fatty acid <br /> d. carbohydrate <br /> e. contains all of the above <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> benzene group <br />_____ 18. The following amino acid is ____. | <br /> H2N-C-C=O Hint :examine R group <br /> | | <br /> a. non-polar H OH <br /> b. neutral and polar <br /> c. basic <br /> d. acidic <br /> e. ask Mickee. <br /> <br />_____ 19. Mitochondria function in _________________. <br /> <br /> a. energy production <br /> b. protein synthesis <br /> c. glycolysis <br /> d. genetic instructions <br /> e. waste disposal <br /> <br />_____ 20. ATP serves as ____________, in energy transfer reactions. <br /> <br /> a. a nucleotide unit in RNA and DNA <br />b. a end products of gluconeogensis <br /> c. a end product of transamination <br /> d. a enzyme <br /> e. a energy currency <br /> <br />_____ 21. The enzymes for protein digestion are called? <br /> <br /> a. peptidases. <br /> b. amylases. <br /> c. hexokinases. <br />d. glyosidases. <br /> e. nucleases. <br /> <br />_____ 22. Glycolysis________ . <br /> <br /> a. requires oxygen, end product is only pyruvate <br /> b. represents the anaerobic anabolism for glucose, ATP production, and <br /> NADH, H+ production, and pyruvate formation <br /> c. represents the splitting off of glucose residues from glycogen <br />d. represents the anaerobic catabolism of glucose to lactate and ATP production <br /> e. represents the anaerobic catabolism of glucose to pyruvate and <br /> nothing else <br /> <br />_____ 23. The end result of beta-oxidation (fatty acid spiral) of FAs? <br /> <br /> a. glucose <br /> b. NAD+ <br /> c. acetyl-SCoA <br /> d. glycerol <br /> e. FAD <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />_____ 24. Identify the chiral carbon in the compd. below. <br /> <br /> H a. a only <br /> | b. b only <br /> a Cl-C-H c. c only <br /> | d. a and b <br /> b Cl-C-OH e. b and c <br /> | <br /> c H-C-H <br /> | <br /> H <br /> <br />______ 25. Given the following enzyme substrate relationship: <br /> <br /> <br /> amylase and glycogen <br /> <br /> Which of the tests listed below demonstrates that the enzyme amylase <br /> would be active <br /> <br /> a. glucose test strip is positive for glucose <br /> b. IKI (starch Iodine test) is dark blue for carbohydrate <br />c. phenolphthalein turns pink due to ammonia formation <br /> d. no Rx because wrong substrate-enzyme relationship <br /> e. not enough information to answer the question <br /> <br />_____ 26. Active transport has a(n) ________ requirement <br /> <br /> a. ATP <br /> b. GTP <br /> c. CTP <br /> d. UTP <br /> e. all above are required for active transport <br /> <br /> <br />____ 27. Methionine, which is common to many proteins, would test positive with the _________ reagent. <br /> <br /> a. Xanthropetic <br /> b. Millons <br /> c. Lead acetate <br /> d. Biuret <br /> e. Seliwanoff <br /> <br />______ 33. Following treatment with Pb (lead), what will happen to any enzyme? _________ . <br /> <br /> a. the enzyme will denature and all activity stops <br /> b. nothing will happen <br /> c. the enzyme will be activated <br /> d. the sulfur groups will react with lead <br /> e. a and d <br /> <br /> <br /> <br />_______ 34. A major control element in the metabolism of lipids, carbohydrates, and proteins is ___________ . <br /> <br /> a. acetyl-SCoA <br /> b. pyruvate <br /> c. acyl-SCoA <br /> d. all of the above <br />d. none of the above <br /> <br /> <br /> <br /> <br />________ 39. This following conversion Rx is an example of an __________ reaction. <br /> <br /> + H2O <br /> cyclopentene ----------> cyclopentanol <br /> <br /> a. hydration <br /> b. reduction <br /> c. halogenation <br /> d. substitution <br /> e. none of the above <br /> <br /> <br />______ 42. _________ is the common functional group identification for an alcohol. <br /> <br /> a. R'-O-R" <br /> b. ROH <br /> c. R-O-SH <br /> d. RCOOH <br /> e. none of the above <br /> <br /> <br />_______ 43. The conversion of glucose 6 phosphate into fructose 6 phosphate is an example of a(n) _____ enzyme. <br /> <br /> a. isomerase <br /> b. hydratase <br />c. reductase <br /> d. oxidase <br />e. none of the above <br /> <br />_______ 44. Albumin can function as ___________ > <br /> <br /> a. a buffer <br /> b. a lipid carrier <br /> c. a single amino acid <br /> d. a buffer and lipid carrier <br /> e. a buffer, lipid carrier, and an amino acid <br /> <br /> <br />______ 45. In blood serum, _________ ratio would represent an ideal condition. <br /> <br /> a. a high HDL/LDL > 1 <br /> b. a low HDL/LDL > 1 <br /> c. a high VLDL/HDL > 1 <br /> d. a low VLDL/HDL > 1 <br /> e. none of the above <br /> <br />_______ 46. The following amine is classified as a _________ . <br /> <br /> a. primary CH2-CH3 <br /> b. secondary | <br /> c. tertiary H-N-CH3 <br /> d. quantenary | <br /> e. penetenary CH3 <br /> <br />_______ 47. A drug that interacts with a receptor to produce or enhance its normal response is called a(n) ________. <br /> <br /> a. agonist <br /> b. amino acid derivative <br /> c. antagonist <br /> d. hormone <br /> e. steroid <br /> <br />______ 48. Which compd. classification would not be found on the inner surface of a cell membrane, since there is no requirement for an antigenic response? <br /> <br /> a. carbohydrates alone <br /> b. glycoproteins alone <br /> c. glycolipids alone <br /> d. glycoproteins and glycolipids <br /> e. all above could be found in any combination <br /> <br /> <br />_____ 49. All of the following types of molecules function as chemical messengers except: ________________ . <br /> <br />a. polypeptide hormones such as insulin <br />b. steroid hormones such as progesterone <br />c. neurons, including axons and dendrites <br />d. amino acid derivatives classified as catecholamines <br />e. neurotransmitters such as acetylcholine <br /> <br />_____ 50. Which statement about a polypeptide hormone is incorrect? <br /> <br />a. hormone class produced by the pituitary <br />b. an example is vasopressin <br />c. insulin is an example <br />d. sex hormones are an example <br />e. may include the releasing hormones <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />_____ 51. All of the following are for energy transfer reactions in biochemical <br />processes except? <br /> <br />a. glycogen must be easily accessible <br />b. stored energy must be released in a controlled manner, i.e. steps <br />c. energy for endergonic reactions require ATP <br />d. NAD+ can be used to drive unfavorable chemical reactions <br />e. mark this if all of the above are true <br /> <br /> <br />_____ 52. The biochemical process in which three individual fatty acids are combined with glycerol to make a triacylglycerol is ______ and called ______. <br /> <br />a. Anabolism; lipogenesis <br />b. Anabolism; fatty acid spiral <br />c. Catabolism; lipogenesis <br />d. Catabolism; fatty acid spiral <br />e. none of the above <br /> <br />_____ 54. ATP is the molecule most often used for the transfer of energy. Which one of the following statements is false? <br /> <br />a. a relatively large amount of energy is release upon hydrolysis of its two phosphoric acid bonds. i.e. explosive, 1000 kcal <br />b. its hydrolysis release an intermediate amount, 7.3 kcal <br />c. it can be produced directly from glycolysis <br />d. its production is an energy requiring process through the cytochrome <br /> system <br />e. mark this if all of the above are true. <br /> <br /> <br />______ 55. Coupling two different chemical reactions together, such as the hydrolysis of ATP, (the expenditure of ATP), a release of energy so that urea can be made from the Urea cycle, a synthetic process, is necessary because __________________. <br /> <br />a. it lowers the activation energy of both of the reactions <br />b. it increases the activation energy of both reactions <br />c. converts an exergonic reaction to an endergonic reaction <br />d. converts an endergonic reaction into and exogonic reaction <br />e. an exergonic reaction drives an endergonic one <br /> <br />_____ 56. Which statement concerning the co-enzymes NAD+ is true when: <br /> <br />NAD+ ---------- NADH, H+ <br /> <br />a. this is a process of oxidation <br />b. this is a process of reduction <br />c. this is a process of hydration <br />d. this is a process of hydrogenation <br />e. none of the above <br /> <br />_____ 57. Every turn of the citric acid cycle directly produces NADH, H+? <br /> <br />a. 1 <br />b. 2 <br />c. 3 <br />d. 4 <br />e. 5 <br /> <br />_____59. The fourth stage of metabolism, in which the high energy molecules from stage three (Kreb's cycle) are oxidized to produced ATP is referred to as <br /> <br />a. active transport <br />b. reductive phosphorylation <br />c. oxidative phosphorylation (electron transport) <br />d. glycolysis <br />e. none of the above <br /> <br />_____ 60. The driving force, which provides the energy for the synthesis of ATP in the fourth stage of metabolism, is the _____. <br /> <br />a. the endergonic conversion of ADP to ATP <br />b. the hydrogen ion concentration difference between the inner and outer mitochondria membranes <br />c. the concentration of oxygen in the cell <br />d. the concentration of glucose in the cell <br />e. all of the above <br /> <br /> <br />_____ 61. The terminal acceptor in the fourth stage of metabolism for the <br />hydrogens from NADH, H+ is a molecule of ____. <br />(Hint: it is group VI AND period 2 molecule and water is produced) <br /> <br />a. water <br />b. carbon dioxide <br />c. pyruvate <br />d. oxygen <br />e. sulfu <br />f. <br />_____ 63. The fatty acid spiral as it relates to the catabolism of a fatty acid can best be described as one in which _______ . <br /> <br />a. the product of the first reaction is the starting material for <br /> for the next reaction in a linear fashion <br />b. a complicated series of chemical reactions which regenerate the <br />the same starting material for the spiral sequence <br />c. no connections between any of the reactants or products in the <br />continuous spiral sequence. <br />d. the same set of enzymes, sequentially tearing down fatty acids in preparation for their entry in the Kreb's cycle as acetyl-SCoA <br />e. The same set of enzymes, adding two carbons one step at a time to the length of fatty acids chains , preparing them to be added to a glycerol molecule for lipogenesis. <br /> <br />______ 64. The reaction in which ATP is converted to ADP with the release of energy is described as being _____ and classified as ____. <br /> <br />a. hydrolysis; and exergonic <br />b. hydrolysis; and endergonic <br />c. combustion; and exergonic <br />d. combustion; and endergonic <br />e. hydration; exergonic <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />_____ 65. Which of the following pathways pairs are reciprocally regulated? <br /> <br />a. glycolysis and gluconeogensis <br />b. glycogenesis and glycogenolysis <br />c. beta oxidation (fatty acid spiral) and lipogenesis <br />d. all of the above are <br />e. none of the above are <br /> <br />______ 66. Urea form deamination of amino acids is used the production of? <br /> <br />a. purines <br />b. pyrimidines <br />c. purines and pyrimidines <br />d. glucose <br />e. fructose <br /> <br />______ 67. Under anaerobic conditions, pyruvate (pyruvic acid) is directly converted to __________. <br /> <br />a. ethanol or lactate <br />b. acetyl-SCoA <br />c. citrate <br />d. steroids <br />e. a purine ribonucleotide (all types) <br /> <br />______ 68. Glycerol 3-phosphate, is the link to glycolysis from which <br />hydrolysis product of the triacylglycerols? <br /> <br />a. fatty acids <br />b. glycerol <br />c. fatty acids and glycerol <br />d. amino acids <br />e. none of the above <br /> <br />______ 69. Overproduction of insulin causes ____, a state in which the concentration of circulating plasma glucose is _____ than normal. <br /> <br />a. hypoglycemia; lower <br />b. hypoglycemia; higher <br />c. hyperglycemia; lower <br />d. hyperglycemia; higher <br />e. none of the above <br /> <br />_____ 70. In an individual who is starving or fasting for prolonged periods of time,the body meets its energy requirements for glucose by the process of _____, and then by the process of _______. <br /> <br />a. glycolysis; gluconeogenesis <br />b. glycogenolysis; gluconeogenesis <br />c. gluconeogenesis; glycogenesis <br />d. glycogenesis; lipogenesis <br />e. lipogenesis; glycogenolysis <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />______ 71. The pentose phosphate shunt is responsible for the production of <br />________ under high demands for DNA replication and transcription. <br />Hint: What goes into making the polymer chains of DNA and RNA. What are the starting materials required? <br /> <br />a. ribose sugars <br />b. pyruvate <br />c. citrate <br />d. glucose <br />e. none of the above <br /> <br /> <br />_____ 72. The co-enzymes involved in carbohydrate catabolism depend on a supply of _______ and carbohydrate anabolism depends on a supply of _______. <br /> <br />a. NAD+; NADH,H+ <br />b. NADP+:NADPH, H+ <br />c. NAD+; NADPH, H+ <br />d. NADH,H+; NAD+ <br />e. NADPH,H+; NADP+ <br /> <br />______ 73. Muscles operating under anaerobic conditions produce high concentrations of lactate, lactate is converted to glucose, in a process called ______ . <br /> <br />a. the Corri cycle <br />b. the Kreb's cycle <br />c. the Fatty acid spiral <br />d. pentose phosphate shunt <br />e. none of the above <br /> <br /> <br />______ 74. If acetyl-SCoA is in higher concentration than can be handled by the Kreb's Cycle, ketone bodies are produced, which one is really a ketone? <br /> <br />a. 3-hydroxybutyrate <br />b. acetoacetate <br />c. acetone <br />d. 5-hydroxybutyrate <br />e. none are ketones <br /> <br />_____ 75. Ketone bodies can originate from the carbon skeletons of _______ . <br /> <br />a. carbohydrates <br />b. lipids <br />c. proteins <br />d. lipids and proteins <br />e. carbohydrates and protein <br /> <br />______ 76. Enzymes, which hydrolyze triacylglycerols, are called: _______. <br /> <br /> a. lipases <br /> b. proteases <br /> c. amylases <br /> d. nucleosides <br /> e. none of the above <br /> <br /> <br /> <br /> <br />_____ 77. Chemical digestion of lipids begins where? <br /> <br /> a. mouth <br /> b. stomach <br /> c. mouth and stomach <br /> d. small intestine <br /> e. large intestine <br /> <br />_____ 78. After treating triacyglycerols with lipases, they pass into the cells of the villi of the small intestine where they are than repackaged as _____________ for transport to the liver. This is the exogenous source of lipids, and these carries are dedicated solely to that the transport exogenous source of lipids. <br /> <br /> a. chylomicrons <br /> b. ultra-high-density-lipoproteins <br /> c. high-density-lipoproteins <br /> d. low-density-lipoproteins <br /> e. very-low-density lipoproteins <br /> <br />______ 79. The lipoprotein carrier, which is, dedicated to the transport of lipids, which are derived form, an excess of dietary protein and carbohydrate is the ______. <br /> <br /> a. very low density lipoproteins <br /> b. low density lipoproteins <br /> c. medium density lipoproteins <br /> d. high density lipoproteins <br /> e. chylomicrons <br /> <br />_____ 80. The first step in the complete hydrolysis of TAGs produces _______ . <br /> <br /> a. glycerol and three fatty acids <br /> b. partial break down to phospholipids, fatty acids and glycerol <br /> c. re-esterification back to TAGs <br />d. triacylglycerols are directly converted to cholesterol <br /> e. direct conversion of glycerol to pyruvate and fatty acids to <br />acetyl-SCoA <br /> <br />_____ 81. If lipid catabolism produces more acetyl-SCoA than the Kreb's Cycle <br />can consume because of reduced need for ATP, (increasing ATP concentration) than the process of ______________ occurs. <br /> <br /> a. gluconeogensis <br /> b. ketogenesis <br /> c. lipogenesis <br /> d. steroid synthesis <br /> e. none of the above <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />_____ 82. In the process of lipogenesis, which coenzyme would be involved in this catabolic process? Id which direction that co-enzyme must operate. (Hint: the process of synthesis is always reduction. Each of the added fatty acids must be reduced with hydrogen as they are added. Oxidation and reduction must always occur at the same time. This is redox!!) Think what happens to coenzyme when it undergoes oxidation. <br /> <br /> a. NAD+ ---------> NADH, H+ <br />b. NADH, H+ ------> NAD+ <br />c. NADP+ --------> NADPH,H+ <br />d. NADPH, H+ ------> NADP+ <br />e. only the shadow knows for sure (none of the above) <br /> <br />_____ 83. If the concentration of ATP in the cell controls the conversion of <br /> conversion of glucose to glucose 6 phosphate, this is an example of <br />what kind of control mechanism. (Hint: control based on a inhibitor, which does not resemble the substrate, which was changed to product at the active site). <br /> <br /> a. allosteric <br /> b. competitive <br /> c. non-competitive <br /> d. helper competitive <br /> e. lock and key <br /> <br />______ 84. Which statement best summarizes the digestive process of proteins? <br /> <br /> a. amine groups are removed from all amino acids during this process. <br /> b. all peptide links are hydrolyzed to produce an amino acid pool <br /> c. stomach acids denature proteins <br /> d. amino acids are combined to make new proteins and enzymes <br /> e. none of the above <br /> <br />_____ 85. Which of the following enzymes are not involved in the hydrolysis of the peptide bonds? <br /> <br /> a. pepsin <br /> b. trypsin <br /> c. amylase <br />d. carboxypeptidase <br /> e. chymotrypsin <br /> <br />_____ 86. The amino acid pool is a collection of _________ . <br /> <br /> a. all the amino acids available from the diet <br /> b. amino acids produced from the break down of proteins and reused. <br /> c. essential amino acids from diet <br /> d. nonessential amino acids made by the organism <br /> e. all the free amino acids in the body, either essential or <br /> nonessential <br />a.b. all the amino acids in the both, both essential and nonessential; found either as free amino acids or found in proteins. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />_____ 87. The common feature of the catabolism of all amino acids is the following: (Hint: think about how energy is going to be produced) <br /> <br />a. removal of an amino group and the remaining carbon skeleton <br /> can end up as intermediates, which can be converted to pyruvate, <br />acetyl-SCoA, and other components of the Kreb's cycle. <br />b. the direct hydrolysis of peptide linkages and the production of carbon dioxide. <br />c. the hydrolysis of peptide linkages to add amino acids to the amino <br /> acid pool; with the production of urea. <br />d. diversion of the remaining carbon skeletons; shuttle them into the <br /> process of gluconeogenesis <br />e. diversion of the remaining carbon skeletons directly into ketone bodies. <br /> <br />______ 88. Carbon Dioxide a waste product of the Citric Acid Cycle and the breakdown of amino acids into carbon skeletons are carbon dioxide and amino groups. Ammonia and carbon dioxide. These are converted to ________ . <br /> <br /> a. urea via the Urea cycle <br /> b. lipids via the lipogenesis cycle <br /> c. carbohydrates through glycolysis <br /> d. proteins though protein synthesis <br /> e. DNA, via replication <br /> <br />_____ 89. An essential amino is part of the amino acid pool, it is described as being; _______________________ . <br /> <br /> a. required in the synthesis of all proteins <br /> b. must be obtained in the diet, species can not manufacture. <br /> c. can be omitted from the diet without any consequences <br /> d. must be provided in the diet if the organism has a <br /> genetic deficiency which prevents the formation of <br /> as specific amino acid, if the organism normally <br /> makes all the common 20 amino acids. <br /> e. has a simple carbon skeleton. <br /> <br />______90. The formation of urea is described as being _____ and would require ______ in order for it to proceed favorably. <br /> <br /> a. anabolic; ATP <br /> b. anabolic; ADP <br /> c. catabolic; ATP <br /> d. catabolic; ADP <br />e. neither catabolic or anabolic; neither ATP or ADP <br /> <br />_____ 91. A amino acid which whose carbon skeleton can be converted to a <br />Kreb's Cycle intermediate, which later becomes a ketone body is called a ________ . <br /> <br /> a. ketogenic amino acid <br /> b. glucogenic amino acid <br /> c. ketone <br /> d. aldehyde <br /> e. ester <br /> <br /> <br /> <br /> <br /> <br />_____ 92. The ammonia which is produced from the removal of the amino groups from amino acids can be used for the synthesis of _______ among other intermediates. Choose one from below. <br /> <br /> a. purines and pyrimidines <br /> b. purines only <br /> c. pyrimidines only <br />d. acetyl-SCoA <br /> e. fumarate <br /> <br />_____ 93. The inability to make tyrosine from phenylalanine is a genetic <br /> defect called: ________ . <br /> <br /> a. PKU <br /> b. UPK <br /> c. KPU <br /> d. Xenobiotics <br /> e. AIDS <br /> <br />______ 94. The catabolism of the amino acid carbon skeletons (amino acids which have had their amino groups removed; occurs in the _______ . <br /> <br /> a. mitochondria <br /> b. cytoplasm <br /> c. mitochondria and cytoplasm <br /> d. chloroplasts <br /> e. mitochondria, chloroplasts, and cytoplasm <br /> <br />______ 95. If a chemical messenger which is carried by the blood stream <br /> is capable of passing through the cell membrane of a cell, the <br /> chemical messenger is probably _______ messenger. <br /> <br /> a. lipid soluble <br /> b. water-soluble <br /> c. could be lipid or water-soluble <br /> d. lipase soluble <br /> e. carbohydrate based <br /> <br />______ 96. If a protein contains the following amino acid sequence, the <br /> protein would most likely have the following characteristics? <br /> <br /> H2N-Ala100-Glu50-Met-Try-Val-Leu-C00H <br /> <br /> a. containing both non polar and acid amino acids <br /> b. containing polar and acidic groups <br /> c. dominated completely by non polar groups <br /> d. cominated completely by acid amino acids <br /> e, none of the above <br /> <br />______ 97. Myoglogin which is found in muscle tissue proper, frequently called muscle hemoglobin, would be what kind of protein? <br /> <br /> a. storage <br /> b. transport <br /> c. structural <br /> d. protective <br /> e. contractile <br /> <br /> <br />98. List the order of events for protein synthesis: <br /> <br /> I. transcription <br /> II. initiation <br /> III. termination <br /> IV. elongation <br /> V, translocation <br /> <br />a. I, II, III, IV, V <br />b. I, II, IV, V, III <br />c. I, II, V, IV, III <br />d. I, III, II, IV, V <br />e. none of the above <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108947727463631532?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1089467952924366442004-07-10T06:58:00.000-07:002004-07-10T06:59:12.923-07:00 Chapter 22 <br /> <br /> Carbohydrate Metabolism <br /> <br /> <br />• the principal role of glucose is as a fuel to yield the energy carried by ATP <br />• muscle cells, nerve cells, and red blood cells rely on glucose as an energy source <br />• the final stages of ATP production begin with acetyl-SCoA, a common intermediate in the catabolism of all food sources <br />• the process of digestion takes the following course <br />1. digestion begins in the mouth with the enzyme alpha amylase <br /> which starts of the process of breaking down complex starches <br /> to sucrose, lactose, maltose <br />2. this digestive process continues in the stomach for about <br /> 1 hour where more digestion is taking place <br />3. these partially digested carbohydrates move into the small <br /> intestine, where the disaccharides are broken down into <br /> monosaccharides, which can be easily absorbed <br /> typical enzymes include: <br /> a. maltase <br /> b. sucrase <br /> c. pancreatin <br /> d. alpha amylase <br />4. these monosaccharides are than absorbed by the villi of the <br /> small intestine and then enter the blood stream <br /> <br /> <br />• see diagram Figure 23.2 <br /> <br /> <br />Metabolic Pathways of Glucose <br /> <br /> <br /> Name Function <br /> <br />glycolysis conversion of glucose to pyruvate <br /> <br />gluconeogenesis synthesis of glucose from amino acids, pyruvate, <br /> and non carbs <br /> <br />glycogenesis synthesis of glycogen from glucose <br /> <br />gylcogenolysis breakdown of glycogen to glucose <br /> <br />Pentose Phosphate conversion of glucose to five carbon sugar phosphates <br /> shunt <br /> <br /> <br />• when glucose enters the cell, it is immediately converted into a form called glucose-6phosphate <br />• this helps keep glucose in the cell by the addition of a phosphate group <br />• this also permits glucose to enter two different pathways, one for the conversion of glucose to pyruvate and processes called glycolysis and the other for the placement of glucose in storage as glycogen a processed called glycogenesis or can be used for the formation of lipid, a process called lipogenesis <br />• in some cells, glucose can enter the pentose phosphate pathway <br /> <br /> sometimes glucose is converted to lactate when oxygen is not present in sufficient concentration, this is necessary to regenerate the oxidized form of the coenzyme NAD+ <br /> sometimes pyruvate is converted back to glucose in a process called gluconeogenesis <br /> <br /> <br />Glycolysis <br /> <br />• this is a process which involves ten enzymatic-catalyzed reactions that breakdown one glucose molecule into two molecules of pyruvate <br />• this process is sometimes called Embden-Meyerhoff <br />• however, other people were involved and their names are not affixed <br />• occurs in the cytosol of all human cells <br /> <br />Steps 1 through 3 <br /> <br /> once glucose enters the cell, it is immediately phosphorylated by an enzyme called a kinase with an investment of one ATP molecule <br /> this process is highly exergonic <br /> this product acts as an allosteric inhibitor of the kinase, if G6P builds up, then glucose is shunted into storage <br /> G6P is isomerized to F6P <br /> F6P is phosphorylated by a kinase to FDP or fructose 1,6 bisphosphate <br /> <br />Steps 4 and 5 <br /> <br /> Fructose 1,6 bisphosphate is broken down into to two three carbon molecules each of which contains a phosphate group, this enzyme is called an aldolase <br /> at the conclusion of these first five steps, two ATP molecules have been invested in this process <br /> dihydroxyacetone phosphate and D-glyceraldehyde 3 phosphate exist in equilibrium with each other <br /> <br /> <br />Steps 6 – 10 Energy Generation Steps <br /> <br /> the purpose of these steps is to generate ATP <br /> Step 6 adds a phosphate to G3P to make a molecule of GDP <br /> this is a critical step because here we make the reduced coenzyme of NADH which can be used in oxidative phosphorylation <br /> Step 7 is called a substrate level phosphorylation because in this step, the phosphate group found on carbon # 1 is transferred to an molecule of ADP to make a molecule of ATP <br /> Step 8 and 9 deal with internal re-arrangement and dehydration to yield a critical product called phosphenopyruvate <br /> <br /> <br />Step 10 <br /> <br /> critical step, phosphoenolpyruvate, here is a phosphate transfer pathway, another substrate level phosphorylation. The final product is now pyruvate, which can enter the mitochondria if oxygen is present. <br /> <br />Remember steps 6 – 10 are repeated twice, this means that there is now a net of <br /> of two ATPs from this cycle. <br /> <br /> <br /> Summary of Glycolysis <br /> <br />conversion of glucose into two pyruvates <br /> <br />production net of two ATPs by substrate level phosphorylation <br /> <br />production of two molecules of NADH, which can be used in the mitrochondria <br /> <br /> <br /> <br /> Fate of Pyruvate <br /> <br /> ultimate fate depends on the presence or absence of oxygen <br /> <br />Aerobic Oxidation <br /> <br /> pyruvate is carried across the mitrochondria into the matrix of the mitrochondria by carrier protein <br /> in this matrix it is converted to acetyl-SCoA <br /> this process involves the use of oxidized NAD which is converted to NADH, which could be used in the generation of additional ATP <br /> <br />Anaerobic Reduction to Lactate <br /> <br /> if a cell which is aerobic becomes oxygen starved, the NADH produced in step 6 page 669 <br /> in step 10 of glycolysis pyruvate accumulated in high concentration because electron transport has slowed <br /> this is an alternative mechanism in the cytosol to regenerate NAD, but to keep glycolysis going, however, at the cost of ATP formation <br /> lactate can be converted to pyruvate at any time in the cell or removed from the cell and brought back as glucose in the Cori cycle page 674 in the liver <br /> <br />Alcoholic Fermentation <br /> <br /> the process of fermentation occurs in the absence of oxygen, as in the case of yeast being used to add alcohol content to a bottle of wine <br /> pyruvate is converted to ethanol and carbon dioxide <br /> <br /> <br /> <br />Energy Output for the Complete Metabolism of Glucose <br /> <br />predicated on the following: <br /> <br /> glycolysis <br /> conversion of pyruvate to acetyl-SCoA <br /> conversion of two acetyl-SCoA to four molecules of carbon dioxide in the citric acid cycle <br /> the passage of reduced coenzymes through electron transport. These coenzymes originate from glycolysis, pyruvate oxidation, and the citric acid cycle <br /> the amount of energy produced varies from 30 – 32 to as high as 38. Some determination put the value at 36. The actual amount is dependent upon whether or not the analysis occurs in a eukaryotic or a prokaryotic cell. It appears that 2 ATPS are lost in a shuttle process/glucose unit moving ATP out of the mitochondria <br /> <br />Regulation of Glucose Metabolism <br /> <br />hypoglycemia = lower than normal blood glucose levels <br /> <br />hyperglycemia = higher than normal blood glucose levels <br /> <br /> normal blood glucose levels are 65 – 110 mg/dl. A deciliter is 100 ml <br /> if blood glucose levels are too low, memory loss and fatigue are frequent symptoms <br /> if blood sugar levels are too high there is frequent low blood pressure and significant urine output <br /> regulation is the result of two hormones from the pancreas, which control blood glucose levels. These hormones are antagonistic toward each other in the control of blood glucose levels <br /> if the glucose levels start to rise in the blood because of a heavy meal, there is a release of insulin from the beta cells of the pancreas. this release has four major effects on the glucose level within the blood stream: <br />1) glucose starts to enter cells more rapidly, apparently, the semi-permeable membrane of the cell has become more permeable to glucose by opening up more gates or making the gates more accessible <br />2) breakdown of glucose by glysolysis is accelerated, apparently insulin through a secondary messenger accelerates the entry of glucose into glycolysis by accelerating the phosphorylation of glucose with ATP in the presence of a kinase <br />3) glycogen synthesis increases to help rid the body of excess glucose <br />4) synthesis of lipids and proteins occurs, this is an alternate form of storage form of excess glucose <br /> under conditions of falling glucose levels, the following four events occur: <br />1) glucose entry into cells slows <br />2) glycogen in the liver starts to breakdown to release more glucose <br />3) breakdown of lipids and proteins to form glucose, as process called <br /> gluconeogenesis <br />4) then gluconeogenesis accelerates <br /> <br /> <br /> <br /> Glycogen Metabolism: Glycogenesis and Glycogenolysis <br /> <br /> glycogenesis occurs when glucose concentrations are high <br /> the process begins with G6P <br /> G6P is isomerized to G1P <br /> G1P is attached to UTP with concurrent loss of a phosphate group <br /> the resulting Glucose-UDP can transfer glucose to a glycogen chain <br /> in removing from storage, a single glucose molecule has a phosphate group added to it w/o an investment of ATP <br /> both synthesis and degradation of glycogen are regulated by the concentration of cAMP. Elevation of the cAMP levels enhances the conversion of glycogen to glucose-1-P by inhibiting the enzyme glycogen synthetase and increasing the glycogen breakdown by activating the enzyme called glycogen phosphorylase <br /> the converse is of course true <br /> the resulting molecule is G1P which can enter glycolysis after it is mutated to G6P by an enzyme called phosphoglucomutase <br /> <br /> <br />see overhead <br /> <br />• the process is different in muscle cells and in liver cells <br />• in muscle cells G6P directly enters the glycolysis pathways <br />• in liver cells, G6P is converted to glucose which can enter the blood stream directly and then this glucose must be transported into the cell for conversion back to G6P which can then enter glycolysis <br /> <br />Glucose from Non carbohydrates: Gluconeogenesis <br /> <br />Cori Cycle <br /> <br />reactions of 1, 3, and 10 are too exergonic to be reversed directly, they require alternate pathways <br /> <br />glycerol from triacyglycerols is converted to dihydroxyacetone phosphate which in turn is converted to G3P at step 5 <br /> <br />carbon atoms from protein breakdown enter at levels as indicated <br /> <br /> <br /> <br /> Pentose Phosphate Pathway (Shunt) <br /> <br />a biochemical pathway that produces a ribose, NADPH and other sugar intermediates from glycolysis, an alternative to glycolysis <br /> <br />the chief function is to produced NADPH an coenzyme needed for the synthesis of <br />lipids <br /> <br />occurs mainly in those places where lipids are produced in high concentration <br /> <br />the other major function is to produce ribose sugars for the synthesis of nucleic acids <br /> <br />two phase process: <br /> <br />1. the oxidative phase converts glucose to Ribulose-5-phosphate <br /> <br />2. the reductive phase converts ribulose-5-phosphate to G3P and F6P which are part of glycolysis in a multi-step process <br /> <br /> <br /> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108946795292436644?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1089467870830629652004-07-10T06:57:00.000-07:002004-07-10T06:57:50.830-07:0028.1 Digestion of Protein <br />The end result of protein digestion is the hydrolysis of all peptide bonds to produce amino acids. <br /> <br />28.2 Amino Acid Metabolism: An Overview <br />The amino acid pool, the entire collection of free amino acids throughout the body, occupies a central position in amino acid metabolism. <br /> <br />Each of 20 amino acids degrades in its own way. However, the general scheme is the same for each one. <br /> Amino Acid Catabolism: <br />Removal of the amino group. <br />Use of nitrogen in the synthesis of new nitrogen compounds. <br />Passage of nitrogen into the urea cycle. <br />Incorporation of the carbon atoms into compounds that can enter the citric acid cycle. <br /> <br /> <br /> Our body don’t store nitrogen-containing compounds. The amino nitrogen from dietary protein has just two fates. <br />It may be used in the synthesis of nitrogen containing molecules such as, <br /> - Nitric oxide - Hormones <br /> - Neurotransmitters - Nicotinamide <br /> - Heme - Creatin phosphate <br /> - Purine and pyrimidine bases <br />Or the amino group must be incorporated into urea and excreted. <br /> <br />28.3 Amino Acid Catabolism: The Amino Group <br />The first step in amino acid catabolism is removal of amino group. In this process, known as transamination, the amino group of the amino acid and the keto group of an a-keto acid change places. <br />There are a number of transaminase enzymes. Most are specific for a-ketoglutarate as the amino group acceptor and work with several amino acids. The a-ketoglutarate is converted to glutamate, and the amino acid is converted to an a-keto acid. <br />28.3 Amino Acid Catabolism: The Amino Group <br />The first step in amino acid catabolism is removal of amino group. In this process, known as transamination, the amino group of the amino acid and the keto group of an a-keto acid change places. <br />There are a number of transaminase enzymes. Most are specific for a-ketoglutarate as the amino group acceptor and work with several amino acids. The a-ketoglutarate is converted to glutamate, and the amino acid is converted to an a-keto acid. <br /> <br />The ionized ammonia formed in the oxidative deamination reaction proceeds to the urea cycle for conversion to urea that is eliminated in the urine. The pathway of nitrogen from an amino acid to urea is summarized in Fig 28.3. <br />28.4 The Urea cycle <br />Ammonia is highly toxic to living organisms and must be eliminated safely. Fish excrete ammonia through their gills directly into the surrounding water and mammals converts ammonia to non-toxic urea via the urea cycle. <br />The conversion of ammonia to urea takes place in the liver. From there urea is transported to the kidneys and transferred to urine for excretion. The biochemical pathway for urea synthesis is shown in Fig 28.4. <br /> <br />28.5 Amino Acid Catabolism: The carbon Atoms <br />The carbon atoms of each protein amino acid are converted to pyruvate, acetyl SCoA, or one of the citric acid cycle intermediates by distinctive pathway, Fig 28.5. Eventually, all the carbon skeleton carbon atoms are used generate energy by passing through the citric acid cycle and gluconeogenesis pathway to form glucose or by entering the ketogenesis pathway to form ketone bodies. <br /> <br />The carbon atoms of the amino acids are converted to the seven compounds shown in the following Fig 28.5. Each of these compound is either an intermediate in the citric acid cycle or a precursor to citrate. <br />28.6 Biosynthesis of Nonessential Amino Acids <br />Humans are able to synthesize about half of the 20 amino acids found in proteins. These are known as nonessential amino acids, because they don’t have to be supplied by our diet. <br />The remaining amino acids, known as the essential amino acids, are synthesized only by plants and microorganisms. Humans must obtain these essential amino acids from food. <br /> <br />All of the nonessential amino acids derive their amino acid from glutamate. <br />Glutamate is also the molecule that picks up the ammonia in amino acid catabolism and carries it to the urea cycle. <br />Glutamate can be made by reductive amination, the reverse of oxidative deamination. <br />Glutamate also provides nitrogen for the synthesis of other nitrogen containing molecules such as purine and pyrimidine. <br /> <br />Glutamine is made from glutamate, asparagine is made by the reaction of glutamine with aspartate. <br />The amino acid tyrosine, classified both as essential and nonessential amino acid since we can synthesize it from phenylalanine. <br />We have a high nutritional requirements for phenyl alanine, and several metabolic diseases are associated with defects in the enzymes needed to convert it to tyrosine and other metabolites. The best known of these diseases is phenylketonuria (PKU). <br /> <br />Phenylketonuria (PKU) results in elevated concentration of phenylalanine, phenylpyruvate, and several other metabolites in the blood serum and urine. <br />Undetected PKU causes mental retardation by the second month of life. <br />All hospitals in the United States now routinely screened newborn babies for treatable PKU. <br />Treatment consists of a phenylalanine free formula for infants and for adults diet free of any meat or other protein containing food. <br />Chapter Summary <br />Protein digestion begins in the stomach and continues in the small intestine. <br />The result of digestion is the complete hydrolysis of proteins to free amino acids. <br />Each amino acid is catabolized by a distinctive pathway, but in most of them amino acid is removed by transamination, usually to form glutamate. <br />The amino group of glutamate is removed as ammonia by oxidative deamination. <br />Chapter Summary Contd. <br />The carbon atoms of proteins are converted to fatty acids or glycogen for storage, or for synthesis of ketone bodies. <br />The net result of urea cycle is the conversion of ammonium ion to urea. <br />Essential amino acids must be obtained from our diet since our body can not synthesize them. <br />Our body can synthesize nonessential amino acids. The nitrogen in these amino acids is commonly supplied by glutamate. <br /> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108946787083062965?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1089467631110704162004-07-10T06:53:00.000-07:002004-07-10T06:55:53.606-07:00Lipid transport mechanisms <br />Chylomicrons <br />Serum albumin <br />VLDL <br />LDLHDL <br /> <br /> <br />Sources of triglycerides for metabolism <br />Diet <br />Storage in adipose tissue <br />Synthesis in the liver <br />Chylomicrons <br />The least dense of the lipoproteins of the transport mechanisms <br />Required for the exogenous lipid transport to the liver <br /> <br />Serum albumin <br />Responsible for the transport of endogenous lipid transport form fat cells <br />VLDL <br />Transport of TAGs manufactured by the liver to fat cells and other cells, tissues, organs where they may be needed <br />LDL <br />Higher in the density of lipid transport mechanisms <br />Often called bad cholesterol <br />Carries cholesterol from the liver to peripheral tissues where it can be used in <br />Steroid hormones <br />Cholesterol synthesis for cell membranes <br /> <br /> <br />HDL <br />Highest of the density of protein carriers <br />Responsible for the transport of cholesterol from worn out cells to the liver for destruction as bile salts <br />Often called good cholesterol <br />25.3 Triacylglycerol Metabolism:An Overview <br />Fig 25.6 The metabolic pathways for triacylglycerols are summarized. <br /> <br /> <br />The fate of glycerol is carried to the liver where it is converted to <br />DHAP which is then converted to glyceraldehyde 3-phosphate <br /> - Glycolysis – energy generation <br /> - or Gluconeogenesis – glucose formation <br /> - Triacylglycerol synthesis: starts with DHAP conversion to glycerol-3-phosphate <br />Glycerol-3-phosphate then has two fatty acids added to make a diacylglycerolphosphate <br />This diacylglycerol phosphate has the phosphate group cleaved and another fatty acid added <br /> <br /> <br /> Acetyl SCoA participates in: <br /> - Triacylglycerol synthesis <br /> - Ketone body synthesis <br /> - Synthesis of steroids and other lipids <br /> - entrance into the Citric acid cycle and then used for oxidative phosphorylation to make ATP <br /> <br />25.4 Storage and Mobilization of Triacylglycerols <br />After a meal, blood glucose levels are high, insulin level rises, and glucogen levels drop. Glucose is entering cells and glycolysis is proceeding actively. Under this conditions, insulin activates the synthesis of TAG for storage from glycerol 3-phosphate and fatty acid acyl group carried by coenzyme A. <br /> <br /> TAG Mobilization <br />After the digestion of a meal is finished, blood glucose levels drop so the insulin level drops and glucagon level rise. <br />The lower insulin level and higher glucagon level together activate triacylglycerol lipase, the enzyme that controls hydrolysis of stored TAG. <br />When there is a short supply of glycerol 3-phosphate, indicates glycolysis is not producing sufficient energy, the fatty acids and glycerols which are the products of TAG hydrolysis are released to the bloodstream for transportation to the energy-generating cells, the cells which are in need <br />25.5 Oxidation of Fatty Acids <br />Oxidation of fatty acid in a cell that needs energy proceeds by the following three steps: <br />Step 1. Fatty acid is activated by conversion to fatty acyl-SCoA, a form that can be broken down more easily. <br />Step 2. Fatty acyl-SCoA is transported into the mitochondial matrix where energy generation takes place. <br />Step 3. Oxidation occurs by repetition of the series of four reactions. <br />25.6 Energy from Fatty Acid Oxidation <br />The total energy out put from fatty acid catabolism is measured by the total number of ATPs produced. First we need to know the total number of acetyl-SCoA produced. Each acetyl-SCoA produces 10 ATPs. Each b-oxidation produces 4 ATPs. Number of repetition is always one less than the number of acetyl-SCoa produced since the last repetition of b-oxidation cleaves a four carbon chain to give two acetyl-SCoa. Also we must subtract 2ATPs spent in activation of fatty acid. <br /> <br />For example, a 12 carbon fatty acid, Lauric acid, produces 78 ATPs. <br /> <br />12 carbon atoms/2 = 6 acetyl-SCoA <br />10 ATPs/acetyl-SCoA x 6 acetyl-SCoA = 60 ATPs <br />-2 ATPs for fatty acid activation <br />6 acetyl-SCoA – 1= 5 b-oxidation <br />4 ATPs / b-oxidation = 20 ATPs <br />Total ATPs produced = 60 + 20 -2 = 78. <br /> <br />Fig 25.8 Summary of pathways of nutrients through anabolism and catabolism <br />25.7 Ketone Bodies and Ketoacidosis <br /> If catabolism produces more acetyl-SCoA than the citric acid cycle can handle, excess acetyl-SCoA is converted to 3-hydroxybutyrate and acetoacetate by liver’s mitochondria. <br />Acetoacetate undergoes spontaneous non-enzymatic decomposition to acetone. <br />3-hydroxybutyrate, acetoacetate, and acetone together known as ketone bodies even though only one of the three compds is actually a ketone <br /> <br />Ketone bodies are produced by a process known as ketogenesis occurs in four enzyme catalyzed steps. <br />Under well-fed, healthy conditions, skeletal muscles derive a small portion of their energy needs from acetoacetate because glucose is supplying all the energy demands of the active cell <br />In a situation when energy production from glucose is not adequate due to starvation or because glucose is not metabolized due to diabetes the production of ketone bodies accelerates since acetoacetate and 3-hydroxybutyrate can be converted to acetyl-SCoA for oxidation in the citric acid cycle. <br /> <br />Under condition of diabetes, ketone bodies are produced faster than utilized, a condition known as ketosis. <br />Because two of the three ketone bodies are carboxylic acids, continued ketosis lead to serious condition known as ketoacidosis. The blood’s buffers are over whelmed and blood pH drops. An individual suffers from dehydration due to increased urine flow, labored breathing since acidic blood is a poor carrier of oxygen, and depression. Ultimately, if untreated, the condition leads to coma and death. <br />25.8 Biosynthesis of Fatty Acids <br />The biochemical pathway for synthesis of fatty acids from acetyl-SCoA is known as lipogenesis. Fatty acid synthesis and catabolism are similar in that they both proceed two carbon atoms at a time. But the two pathways are not exactly reverse to each other. <br />The following two reactions set the stage for lipogenesis: (1) transfer of an acyl group from acetyl-SCoA to a acyl carrier protein (ACP) and (2) Conversion of acetyl-SCoA to malonyl-SCoA. <br /> <br />Once acetyl-SACP and malonyl-SACP are generated a series of four reactions lengthens the fatty acid chain by adding two carbon atoms with each repetition. Fatty acids with up to 16 carbon atoms (palmitic acid)are produced by this method. Larger fatty acids are produced from palmitoyl-SCoA with the aid of specific enzyme. <br />Chapter Summary <br />Triacylglycerols (TAGs) from the diet are broken into small droplets in the stomach and enter the small intestine, where they are emulsified by bile acids and forms micelles. <br />Pancreatic lipases partially hydrolyze the TAGs in micelles. <br />Small fatty acids and glycerols from TAGs hydrolysis are absorbed directly in to the blood stream. <br />Chapter Summary Cond. <br />Insoluble hydrolysis products are reassembled into TAGs. These TAGs are reassembled into lipoprotein chylomicrons and absorbed into the lymph system for transport to the bloodstream. <br />In addition to chylomicrons <br />Very-low-density-lipoproteins (VLDLs) carry TAGs synthesized in the liver to peripheral tissues for energy generation or storage. <br /> Low-density-lipoproteins (LDLs) transport cholesterols from the liver to peripheral tissues for cell membranes or steroid synthesis. <br />Chapter Summary Contd. <br /> High-density-lipoproteins (HDLs) transport cholesterols from peripheral tissues back to the liver for conversion to bile acids that are used in the digestion or excreted. <br />Dietary TAGs undergo hydrolysis to fatty acids and glycerol-3-phospahate by enzymes. Fatty acids undergo b-oxidation to acetyl-SCoA or resynthesis into TAGs for storage. <br />Acetyl-SCoA can participate in resynthesis of fatty acids (lipogenesis), formation of ketone bodies (ketogenesis), steroid synthesis, or energy generation via citric acid cycle and oxidative phosphorylation.(10 step pathway) <br />Chapter Summary Contd. <br />Glycerols can participate in glycolysis, gluconeogenesis, or TAG synthesis. <br />Synthesis of TAGs for storage is activated by insulin when glucose levels are high, typical when following a heavy meal. <br />Utilization of lipids occurs when glucose levels are low and the enzyme glucagon now kicks in, typical when carbohydrates reserves are low or starvation conditions exist <br />Fatty acid oxidations are activated by conversion to fatty acyl Coenzyme A. The fatty acyl-COA are transported into the mitochondrial matrix and are then oxidized two carbon atoms at a time to acetyl-SCoA by repeated trips through the b-oxidation spiral. <br />Chapter Summary Contd. <br />The ketone bodies (3-hydroxybutyrate, acetoacetate, and acetone) are produced when the energy generation from citric acid cycle cannot keep up with the quantity of acetyl-SCoA that is available which can enter the citric acid cycle. This is a “dump pathway” so the cells in need of energy can convert 3-hydroxybutyrate to acetyl-SCoA. In this way, acetyl-SCoA is made available for energy generation when glucose is short supply. <br /> <br />This is the end <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108946763111070416?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1089467539957808922004-07-10T06:52:00.000-07:002004-07-10T06:56:37.653-07:0025.1 Digestion of Triacylglycerols <br />Lipid metabolism is the second most important source of energy in our body. Majority of the lipids in our diet are triacyglycerols (TAG), therefore, metabolism of triacylglycerols, which are stored in our fatty tissue, constitute a chief energy reserve source <br /> <br />When eaten, triacylglycerols pass through the mouth virtually unchanged and enter into the stomach where the heat and churning action of the stomach breaks lipids into smaller droplets. <br />Mechanical action of the churning of the stomach <br />The lipids leave the stomach in a package called chyme <br /> <br /> <br /> <br />The hydrophobic lipid droplets are packaged in the small intestine various kinds of <br />Lipoproteins. This is necessary in order for the hydrophobic lipids to move about in aqueous environments. <br /> <br />The efforts of the small intestine <br />The lipids must be prepared to be attacked by the enzymes of the small intestine <br />Here bile salts are added in the duodenum to help the action of the lipases <br />These behave as detergents <br />These resemble soaps which allow the lipids to become more soluble in the aqueous environment <br />Finally the low pH of the chyme is raised to pH = 8 <br /> <br />Partially digested lipids (mechanical) are partially hydrolyzed in the upper intestine with the help of bile released by the gallbladder and the enzyme pancreatic lipases to mono and diacylglycerols, fatty acids and a small amount of glycerol which is then absorbed in the cells of the small intestine through facilitated diffusion. Glycerol and some of the smaller fatty acids are absorbed in the cells of the villi <br /> <br />These water soluble smaller fatty acids and glycerols enter into the blood stream and carried to the liver through the intestinal veins and enter the hepatic portal vein which goes to the liver where chemicals processes occur: <br />Glycerol is converted to through DHAP <br />This can be used to make glycogen <br />DHAP is Isomerized to glyceraldehyde-3-phosphate to make ATP through glycolysis <br /> The smaller fatty acids are combined with with the glycerol which has been converted to glycerol-3-phosphate and return to storage <br /> <br />Digestion of the larger lipids <br />The still-insoluble acylglycerols and larger fatty acids are emulsified once again with biles salts <br />They are then packaged into water soluble lipoproteins known as chylomicrons <br />These lipids are released from the chylomicrons once they have entered the cell of the small intestine <br />These mon and diacyglycerides are converted back to triglycerides in the cells of the small intestine <br />These triglycerides are repackaged into chylomicrons again <br />Which are then absorbed by the lacteals <br />They are then sent to inferior vena cava by passing the liver <br /> <br />What are the chylomicrons? <br />Chylomicrons are too large to enter blood stream through capillary walls of the small intestine. Instead, they pass through the cells of the small intestine and are then absorbed by the lymphatic system and carried to the thoracic duct, where the lymphatic system is emptied into the superior vena cava. <br /> <br />Fig 25.4 Pathways of lipids through the villi <br /> <br />Fig 25.4 Pathways of lipids through the villi <br /> <br /> <br />Fig 25.5 Transport of lipids <br /> <br />Lipid transport mechanisms <br />Chylomicrons <br />Serum albumin <br />VLDL <br />LDLHDL <br /> <br /> <br />Sources of triglycerides for metabolism <br />Diet <br />Storage in adipose tissue <br />Synthesis in the liver <br />Chylomicrons <br />The least dense of the lipoproteins of the transport mechanisms <br />Required for the exogenous lipid transport to the liver <br /> <br />Serum albumin <br />Responsible for the transport of endogenous lipid transport form fat cells <br />VLDL <br />Transport of TAGs manufactured by the liver to fat cells and other cells, tissues, organs where they may be needed <br />LDL <br />Higher in the density of lipid transport mechanisms <br />Often called bad cholesterol <br />Carries cholesterol from the liver to peripheral tissues where it can be used in <br />Steroid hormones <br />Cholesterol synthesis for cell membranes <br /> <br /> <br />HDL <br />Highest of the density of protein carriers <br />Responsible for the transport of cholesterol from worn out cells to the liver for destruction as bile salts <br />Often called good cholesterol <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108946753995780892?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1088463124650248902004-06-28T15:51:00.000-07:002004-06-28T15:52:04.650-07:001. Important definitions: <br /> <br />saturated: Containing only single bonds between carbon atoms unable to accommodate additional hydrogens. <br /> <br />unsaturated: Containing one or more double (=) bond or triple () bonds and able to accommodate additional hydrogens. <br /> <br />alkenes: Containing only carbon and hydrogen and a least one double bond. <br /> <br />alkynes: Containing only carbon and hydrogen and at least one triple bond. <br /> <br />Nomenclature <br /> <br />1. Naming the alkenes and the alkynes. <br /> <br />2. Find the root of the name as you would in the alkane. The longest unbroken chain. <br /> <br />3. You than must determine if there is a double or a triple bond present in the compd. <br /> <br />If there is a double (=) bond, the suffix of ene replaces ane. <br /> <br />i.e. pentane -----> pentene <br /> hexane -----> hexene <br /> <br />If there is a triple () bond, the suffix of yne replaces ane. <br /> <br />In order to properly identify this compd., start with the longest chain containing the double or triple bond. Begin the count nearest the double or the triple and affix the proper suffix. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />The same is true of the triple bonds (). <br /> <br /> <br /> <br /> <br /> <br /> <br />The condensed formulas for the next three structures are shown below. Note in each case the double and triple bonds are shown. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />4. Step 3: Indicate by numbers the positions or the alkyl groups attached to the parent chain. <br /> <br /> <br /> <br /> <br /> <br /> <br />Name ---> 7-methyl-2-octyne <br />not 2-methyl, 6-octyne <br /> <br />again, 7-methyl ---> prefix <br />2 ---> prefix <br />oct ---> root <br />yne ---> suffix <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />5. Even if both a halogen and an alkyl group are found in the same compd, still start at a position as close as possible to the double or triple bond. When possible assign the lowest possible total assignments. Cite in alpha order. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />6. If there are multiple halogen attached, than the appropriate designations of di, tri, tetra, etc must be affixed. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />7. Here is what happens if you have multiple alky groups in the same compd. Start nearest the first branch in this example. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Geometric Isomerism <br /> <br />1. In describing the geometry of organic compds, if there are four separate bonds attached to a central carbon atom, than the geometry about that carbon is described as tetrahedral. <br /> <br />2. In describing the geometry of organic compds, if there are two single bonds and one double bond attached to a central carbon atom, then the geometry about that carbon is described as planar. <br /> <br />3. In describing the geometry of organic compds, if there are two double bonds attached to a central carbon atom, than the geometry about that carbon is described as linear. O=C=O <br /> <br />4. In describing the geometry of organic compds, if there is a single and a triple bond attached to a central carbon atom, than the geometry about that carbon is described as linear. H-CC-H <br /> <br />5. When there are carbon - carbon single bonds, there is always free rotation about that bond, giving rise to an infinite number of conformations, which are NOT isomers. <br /> <br />6. The presence of the double bond introduces a new form of isomerism, geometric isomerism. In particular, it is described as cis-trans isomerism. It is geometric because the arrangement of the groups about the double bond is changed. <br /> <br />7. Cis and trans isomerism also occurs about the double bond in a linear alkenes and cycloalkanes. <br /> <br />8. Cis/trans isomerism need not be limited to hydrogen. Anytime two halogens or groups are either on the same side or opposite each other, geometric isomerism exists. <br /> <br />8. Isomerism comes in many forms, it is the word used to described circumstances. Geometric isomerism is a special case of isomerism. <br /> <br />Cis Isomer: Isomer having a specific pair of atoms or groups on the same side of the double bond. The word cis is appropriately described as a prefix. <br /> <br />Note: The designation CH3 = H3C, JUST WRITTEN DIFFERENT. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />A incorrect name for the compd. would be cis 1, 2-dimethyl ethene. The reason is that you must count each of the carbons in the longest continous chain. There are four carbons present with a double bond found on the second carbon. The appropriate name would be: a 2-butene. <br /> <br />Each of the above representations are the same. The double bond is found on C#2. One is written to be read easily, the other is not. <br /> <br />Representations <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />1-butene, 2-butene, and 2-methyl propene are isomers of each other, only 2-butene has cis/trans. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Cis/trans 2-butene is sufficient to identify the compd. You need not worry about identifying the locations of the hydrogens. It is understood that they are there: the absence of a prefix for the presence of other groups. <br /> <br />However, if the compd. was as follows: <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />As written is confusing, however, within the limitations of the paper, both groups pointing in the same direction (up/down) indicates cis/trans isomerism. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Trans Isomer: Isomer with a specific pair of atoms or groups on the opposite side of the double <br />bond. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />9. One caveat: THERE CAN BE NO CIS TRANS ISOMERISM IF TWO IDENTICAL GROUPS ARE ATTACHED TO ONE OF THE CARBONS INVOLVED IN THE DOUBLE BOND. (Some C - H bonds omitted for simplicity.) <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Here two fluorine atoms are attached to C#1, therefore no cis/trans isomerism. <br /> <br />Given ethene with two fluorine atoms attached, there are three possible isomers. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />A, B and C are geometric isomers of each other. <br /> <br /> cis 1,2 trans 1,2 1,1-diflouroethene <br /> <br />There can be no cis/trans isomerism in a triple bond because the molecule is linear! <br /> <br />Possible arrangement of cis/trans depends on the relationship of four groups to each other! <br /> <br />Properties of Alkenes <br /> <br />1. To be an alkene, you must have a double (=) bond between two carbon atoms. <br /> <br />2. If a carbon compound has three or more carbons, the compd. may have both alkane and alkene like character. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />3. Alkenes are non polar, with b.p. and m.p. increasing with increasing carbon length. B.p. and m.p. lower than corresponding alkane. <br /> <br />n-butane vs. 1-butene <br /> <br />b.p. ºC O -6.5 <br /> <br />4. Solubility decreases with increasing carbon length. <br /> <br />5. Cis and trans isomerism is possible about double bond. <br /> <br />6. The double bond undergoes addition and oxidation Rxs. <br /> <br />Nomenclature of the Alkynes <br /> <br />1. Named systematically as in the alkanes. <br /> <br />2. Simplest alkyne is: <br /> <br />H-CC-H ethyne <br /> <br />Name root ---> ethane <br />drop ane and add yne ---> ethyne <br /> <br />H-CC-CH3 ---> propyne <br />propane ---> propyne <br /> <br />not 1 propyne because no substitutions <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Again, always assign the lowest possible number to the triple () bond. <br /> <br />3. Complex names for alkynes have the prefix, root and suffix. This condensed formula clearly shows this relationship. <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />In this case, the triple bond ended up in the same place as in the previous example, however, the branch has a higher number assigned. Need the lowest possible number for the branch. Hence, the functional group is first followed by the branch point. <br /> <br />Properties of Alkynes <br /> <br />1. Non polar compds. <br /> <br />2. Undergo addition and oxidation reactions. <br /> <br />3. M.p. and b.p. similar pattern to corresponding alkane. <br /> <br />4. Solubility decreases with increasing carbon number. <br /> <br />5. Geometry is linear across triple bond. <br /> <br />6. No cis/trans isomerism across triple bond: not possible because triple bond geometry is linear. <br /> <br />Reactions of Alkenes and Alkynes <br /> <br />1. Alkenes and alkynes will typically undergo addition Rxs. Addition Rxs occur across the double bond, which is the functional group and the substitution Rxs will occur across the single bonds, which are the alkane functional group. Where addition or a substitution reaction occurs depends on the reaction conditions employed. <br /> <br />Addition Reaction: Addition of a reactant of the general form X-Y to the multiple bond of a unsaturated compd. to a yield a saturated product, containing only single bonds. Two forms: <br />a. X2: (H2, Cl2, I2) <br />b. HX: (HCl, HI HBr, HOH) <br /> <br />A. Catalytic hydrogenation: unsaturated ---> saturated <br /> <br />Hydrogenation: Rx of an alkene or aklyne with hydrogen in the presence of a metal catalyst [M] to yield an alkane product. <br /> <br />General form: <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />* Always assign the lowest number to branch point in an alkane. Note the change in the ending from ene to ane. <br /> <br />In the above alkenes, the hydrogens could be cis or trans prior to hydrogenation, however, once fully hydrogenated, cis/trans relationship ceases to exist. This is true because there is free rotation about the carbon – carbon single bonds. <br /> <br />Process can also occur in a(n) cyclic alkene. <br /> <br /> + H2/M <br /> <br />cyclohexene cyclohexane <br />no cis/trans no cis/trans <br /> <br />In the previous examples, hydrogens are not shown, need not show them. The condensed structures of the rings are sufficient. If something other than hydrogen was added, than you need only to show the group(s) which were added. <br /> <br /> +H2/M <br /> <br />1-methylcyclohexene ---------> methylcyclohexane <br /> <br />Need to identify the location of the methyl group prior to hydrogenation. If said only methylcyclohexene, these would be another possible structures: <br /> <br /> all are isomers <br /> (hydrogen omitted) <br /> <br />3-methyl 4-methylcyclohexene <br /> <br />Prior note the change from ene to ane. As always, there could be cis/trans isomerism across the double bond. <br /> <br />B. Halogenation: Addition of the following halogens <br />a. Cl2 <br />b. Br2 <br />c. I2 <br /> <br />Halogenation alkene: Addition Rx of a halogen to yield a dihaloalkane. <br />Halogenation alkyne: Addition Rx of a halogen to yield a tetrahaloalkane. <br /> <br />General form: (mixing reactant and halogen) <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Process can also occur in the cycloalkene <br /> <br /> + Br2/CH2Cl2 -----> <br /> (CH2Cl2 is a solvent) <br />cyclohexene 1, 2-dibromocyclohexane <br /> <br /> + Br2/CH2Cl2 -----> <br /> <br />1-methylcyclohexene 1, 2-dibromo, 1-methylcyclohexane <br /> <br />Knowledge Challenge: <br /> <br /> + Cl2/light -----> <br /> <br />1-methylcyclohexene 1-chloromethylcyclohexene <br /> <br /> <br /> <br />3-chloro-1-methylcyclohexene <br />C=C takes highest priority <br />Note: written in alpha order <br /> <br />C. Hydrohalogenation: The Rx to a alkene with HCl of HBr to yield an alkyl halide. <br /> <br />X = halogen a. HCl <br />b. HBr <br /> <br />Where the hydrogen and the halogen finally end up is determined by the following rule of addition: <br /> <br />Markovnikov'sRule: In the addition of HX to an alkene the hydrogen becomes attached to the carbon that already has the most hydrogens (primary carbon) and the halogen becomes attached to the carbon with the fewest, secondary or teritary). <br /> <br />Process include: <br />1. hydrohalogenation <br />2. hydration <br /> <br />Remember: halogenation =/= hydrohalogenation <br /> <br />Halogenation is the addition of the diatomic halogen across the double or the triple bond. <br /> <br />Hydrohalogenation involves the addition of HX across the double bond. Where X = chlorine, bromine or iodine. <br />General form: <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />For those who wanted to know --> the addition of non identical adgenda (HX) to a triple bond follows Markovnikov's Rule. (All you would ever want to know). <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />In order for this process to be succeed, the concentration of the alkyne and haloalkene must be in significant excess! <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Addition to Cycloalkenes <br /> <br />Markovnikov's Rule: The addition of HX to an cycloalkenes included the hydrogen becomes attached to the carbon that already has the most hydrogens and the halogen becomes attached to the carbon with the fewest. <br /> <br /> HOH <br /> (ACID) <br /> <br />1-methylcyclohexene 1-methyl-1-cyclohexanol <br />tertiary carbon tertiary alcohol <br /> <br /> + HCl ----> <br /> <br />cyclohexene chlorocyclohexane <br /> <br /> + HBr ----> <br /> <br />1-methy-1cyclohexene 1-bromo-1-methylcyclolohexane <br /> <br />1. Oxidation: Process in organic chemistry is described as the loss of electrons or hydrogens or the gain of oxygen. <br /> <br />It's collerary --> reduction: The loss of oxygen or the gain of electrons or hydrogen atoms. <br /> <br />Alkenes┆__________ + O2 + heat ----> CO2 + H2O (combustion) <br />Alkynes┆ <br /> <br />D. Hydration alkene: The Rx of an alkene with water and acid to yield an alcohol. Water adds to the more reactive alkenes. Addition follows Markovnikov's Rule. <br /> <br />General form: <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />Hydrogen attaches to C#1 a 1 (primary carbon) -OH attaches to C#2 ==> teritary alcohol <br /> <br />Hydration can also occur in the cycloalkenes. What you need to know about the hydration of the cycloalkenes is limited to the understanding that all cycloalkenes can undergo addition as determined by: <br /> <br />Polymers <br /> <br />1. Polymers are large molecules formed by bonding together many smaller molecules called monomers. <br /> <br />2. These monomers may be identical or different. <br /> <br />3. The molecular weight of the polymers tend to be very large. <br /> <br />4. Many of the common materials you encounter are polymers. <br /> <br />5. Many biological materials are polymers. <br /> <br />6. Polymers do not have to be made up only of alkenes. <br /> <br />7. One of the most common polymers that you encounter every day is PVC, polyvinyl chloride. <br /> <br />8. PVC is made up of the repeating unit called the vinyl group, H2C=CH , or in IUPAC name of ethenyl. <br /> <br />9. Ethylene, H2C=CH2 which is the starting material is polymerized. Polymerization is the process of linking monomers together to form a polymer. <br /> <br />10. The process is described as being chain growth. Meaning that you add one monomer at a time. <br /> <br />11. Like many processes that we have discussed, the process requires a catalyst, however in polymer terms it is called a initiator. <br /> <br />12. Using careful techniques, the molecular weight of the polymer can be controlled. This is important when you want certain properties or the ability to process the polymer. You can also control branching as well. <br /> <br />13. The longer straight chains w/o branching allows for close packing of the chains, giving rise to a rigid structure, having a higher m.p. ==> rigid or high density ==> plastic bottles. Remember increasing the number of (-CH2-) increasing b.p. and m.p. of linear alkanes. Those with branching ==> low density, and more flexible applications ==> plastic wrap. <br /> <br />Aromatic Compds <br /> <br />1. Aromatic compds: A description of a class of compds containing benzene-like rings. Can be heterocyclic as well. <br /> <br /> <br /> <br />benzene a heterocylic <br /> <br />2. The molecule is described as being held together by resonance. This is the type of molecule in which there is no proper way to describe the carbon to carbon bonding relationships. It is frequently described as an electron smear. The bonds that form are not double but not single. They are somewhere between. The structures below represent the possible triene relationship that could describe the possible relationship, however, singlely, neither is correct. Hence the name, electron smear! <br /> <br /> <br /> <br />electron smear <br /> <br />3. A benzene ring that is unsubstituted, is non polar, insoluble in water and not very reactive. Aromatic compds will not react with H+ (hydrogenation), HBr and HCl (hydrohalogenation) and H2O (hydration) under conditions which will reaction with other alkene or alkynes. <br /> <br />4. Benzene like rings are frequently found in many biomolecules. Including the DNA and RNA. <br /> <br /> <br /> Indole Adenine <br />(perfume) (DNA/RNA) <br /> <br />Nomenclature Aromatic Compds <br /> <br />1. Start with the parent compd. in most cases: Benzene <br /> <br />2. Then name as a substituted derivative of benzene. <br /> <br /> <br /> <br />Bromobenzene Ethylbenzene Nitrobenzene <br /> <br />There is only one group on the ring, therefore it is assumed to be C#1. Named as 1 bormobenzene is WRONG! <br /> <br />3. Disubstituted aromatic compds are name using one of the following prefixes, instead of C#1, 2 or 3. Positions described relative to each other in the benzene ring. The use of these prefixes occurs instead of the naming by locants. <br />a. ortho ===> 1, 2 <br />b. meta ===> 1, 3 <br />c. pare ===> 1, 4 <br /> <br /> <br />ortho meta para <br /> <br />4. If groups are identical, in the disubstituted ring apply the prefix di. <br /> <br /> <br /> <br />o-dichlorobenzene m-dichlorobenzene p-dichlorobenzene <br /> <br />5. If the groups substituted are different, you number in alpha order. For testing purposes, disubstituted is where we stop. <br /> <br /> <br />p bromochlorobenzene m chloroethylbenzene <br /> <br />6. Many substituted aromatic compds have common name in addition to IUPAC names. It is a good idea to memorize the name and structure. You will encounter them in lab, exercises and elsewhere. <br /> <br /> <br /> <br />phenol Nitrobenzene Toulene <br /> <br /> <br /> <br />Aniline Benzoic Acid Benzaldehyde <br /> <br />7. If the previous compds have an additional group attached, than the designations of ortho, meta and para is used in conjunction with the common names above. <br /> <br /> <br /> <br />p-chlorotoulene m-chlorotoluene o-chlorotoulene <br /> <br /> <br /> <br />m-nitrophenol o-chlorophenol p-bromophenol <br /> <br />8. Sometimes the benzene ring is considered to be a substitutent, when this happens, the name phenyl is applied. <br /> <br /> <br /> <br /> <br /> <br /> <br /> 3-phenlyheptane <br /> <br />Reactions of Aromatic Compds <br /> <br />1. Aromatic compds undergo several types of reactions. These reactions are described as substitution reactions. These reactions are of the form YX. <br /> <br /> XY ----> + H-Y <br /> <br />benzene <br /> <br />a. Nitration: Substitution of an NO2 for an -H in an aromatic ring <br /> <br /> HNO3/H2SO4 ----> + H2O <br />benzene nitrobenzene <br /> <br />Useful for the production of aniline which is used in many clothing dyes and explosives. TNT is made in a stepwise process: The structure looks something like this: No I can not tell you have the process is exactly done! <br /> <br /> <br /> <br />Toluene TNT <br /> trinitrotoluene <br /> 2, 4, 6-trinitrotoluene <br /> <br /> HNO3/H2SO4----> <br /> <br />Aniline p-nitroaniline <br /> <br />Aniline name used because you started with aniline, just simpler. Could be named p amino nitro benzene. <br /> <br />b. Halogenation: Substitution of -Br or -Cl for -H in an aromatic ring. <br /> <br /> Cl2/Fe ----> <br />benzene (Fe = catalyst) chlorobenzene <br /> <br /> Cl2/Fe ----> <br />chlorobenzene p dichlorobenzene <br /> <br /> Cl2/Fe ----> <br />aniline o-chloroaniline <br /> <br />c. Sulfonation: Substitution of SO3H for an H in an aromatic ring. <br /> <br /> H2SO4/SO3 ----> <br />benzene benzenesulfonic acid <br /> <br />Useful for the production of sulfa-related drugs. <br /> <br /> Cl2/Fe --> <br />benzenesulfonic acid o-chlorobenzenesulfonic acid <br /> <br />d. Hydration: Addition of water, making an alcohol. For exam purpose, recognize that this is the addition on a -OH group to a aromatic or a polyaromatic compd. Know how to get there for a single aromatic compd. only! This hydration process is the "culprit" in the creation of some carcinogens in some polyaromatic compds. <br /> <br /> <br />benzene phenol <br /> <br /> Cl2/Fe ----> <br />phenol p-chlorophenol <br /> <br />Hydrogenation: Addition of hydrogenation. Taking a aromatic compd. and making it a fully saturated hydrocarbon. This is an addition reaction. <br /> <br /> H2/metal ----> <br />benzene cyclohexane <br /> <br />Polyaromatic Compds <br /> <br />1. A(n) organic compd. that has two or more "benzene" like rings fused along their edges is called a polyaromatic compd. <br /> <br /> <br />Napthalene Benz[a]pyrene <br /> <br />Both of these compds fall into this classification. What makes them "benzene" like is the <br />presence of resonance. Each of the rings is capable of undergoing the typical aromatic substitution reactions. <br /> <br />Napthalene: Found in mothballs. It has a high m.p. It will change from a solid to a gas slowly. A process of ? <br /> <br />Benz[a]pyrene: Carcinogenetic. Found in soot. Found in cigarette smoke and burnt meat. Exposure to small quantities can cause tumors. <br /> <br />The problem with Benz[a]pyrene is when the body attempts to rid itself of the compd. by converting it to a alcohol, a process of oxidation, a hydration reaction. Unfortunately, the new compd. binds to cellular DNA and causes a mutation. This is case where the body creates a carcinogen by "trying" to get rid of a foreign compd. <br /> <br />Typically detoxification reactions occurs in the liver. The changed metabolite then moves throughout the body carried blood plasma. Many cancers of this sort tend to be liver cancers, since the concentration of the carcinogen tends to be concentrated in one organ. This is true of many carcinogens if a chemical has an affinity for a "target". <br /> <br />Dyes and Color <br /> <br />Many of the polyaromatic rings are found in dyes. <br /> <br /> <br /> <br />One of the most important of the fused rings compds is beta carotene, an analogue of Vitamin A which is we know is needed for vision. Have you ever seen a blind rabbit? <br /> <br /> <br />Remember, the color that we see, is complementary to the color absorbed. That is, we see what is left of the white light after certain colors are absorbed. Different dyes have different chemical structures. It is these structures which determine the color which is absorbed, that is the color of the dye that we see! <br /> <br />When we treat a compd. with bleach, we are breaking up the resonance in the compd. Therefore, that is why a green compd. treated with bleach becomes white. It is not <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108846312465024890?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1087840620104706682004-06-21T10:54:00.000-07:002004-06-21T10:57:00.103-07:00• protein: a large biomolecule, really a polymer of many amino acids linked together by amide(peptide) bonds <br /> <br />• amino acid: a molecule that contains both an amino group and a carboxylic acid functional group <br /> <br />•  amino acid: an amino acid in which the amino group is bonded next to the –COOH group <br /> <br />• peptide bond: an amide bond that links two amino acids together <br /> <br />• each amino acid contains an “R” group and an amino group bonded to a central carbon atom <br /> <br />• amide bonds are called peptide bonds when they occur in proteins <br /> <br />• a dipeptide results from bonds two amino acids together; one from the amino group and one from the carboxylic acid group of the neighboring amino acid <br /> <br />• tripeptide is three amino acids <br /> <br />• linear chain like polymer of amino acids is a polypeptide <br /> <br /> <br />• the exact order of sequence of this unfolded, linear chain is called primary sequence; which is determined by the information strand of DNA. This is responsible for the following protein structures: <br />o secondary: repeating spatial organization <br />o tertiary: overall shape produced by bending and folding <br /> <br />• quaternary: relationship of two or more polypeptide chains in their 3-D configuration <br /> <br />• see table 18.2 page 486 for classification scheme based on function <br />• structure: collage and keratin; fingernails and hair <br />• catalysts: enzymes <br />• contractile proteins: mechanical work, actin and myosin <br />• protective: IgG, IgA, IgM <br />• storage: myoglobin holds oxygen in muscle tissue <br />• transport: albumin which carry endogenous lipid in the circulatory system <br />• hormones: polypeptide and polypeptide derivatives <br /> <br /> <br /> <br />Amino Acids <br /> <br />• nature uses 20 common amino acids in the building proteins <br /> <br />• see table 18.1 page 484: important function groups <br />a) need to know each functional group <br /> <br />• see table 18.3 page 487: <br />a) know classifications <br />b) do not need to know where each one fits <br /> <br />• 19 have chiral centers, glycine does not <br /> <br />• 19 of the amino acids are similar in that they a primary amines and only proline is a secondary amino acid <br /> <br />• also glycine is the simplest of the amino acids which have as an “R” group hydrogen <br /> <br />• typically describe name of the amino acid w/ a 3 letter code <br /> <br />• the twenty amino acids are classified in the following manner and would have the following characteristics: <br />a) non-polar side chains <br />1) hydrophobic in character <br />2) tends to be found in the center of a folded protein and <br />3) participates in London Force <br />4) creates a water free environment <br /> <br /> <br /> b) polar and neutral side chains <br /> 1) forms hydrogen bonds <br /> 2) hydrophilic <br /> <br /> c) acidic <br /> 1) hydrophilic <br /> 2) ionic <br /> 3) salt bridge w/ base <br /> <br /> d) basic <br /> 1) hydrophilic <br /> 2) ionic <br /> 3) salt bridge w/ acid <br /> <br />central theme points: <br /> <br /> 1) covalent bonds <br />a) disulfide bonds <br /> 2) ionic <br />a) salt bridges <br /> 3) others <br /> a) hydrogen bonding <br /> b) London forces <br /> c) hydrophobic between the non polar <br /> R groups pf the protein <br /> <br /> <br />KEY= water loving AAs tend to be found on the surface of the protein  this gives solubility to the protein in water <br /> <br /> <br /> Acid Base Properties of Amino Acids <br /> <br />• zwitterions: a neutral dipolar ion that has one + and one – charge <br /> <br />• this results when a –COOH group gives up a proton and a –NH2 takes on a proton at physiological pH <br />• the result: <br />• is a COO- <br />• and a NH3+ <br />• a dipolar ion <br /> <br />• AAs should be written in their ionized forms <br /> <br />• because they are ions, they have the following properties <br />o crystalline <br />o high melting points <br />o soluble in water but not hydrocarbon solvents <br />o behave as acids or bases (all acid/base groups) behave differently <br />o in acid solution, they accept hydrogen ions on the basic COO- <br />• see page 490 <br />o in basic solutions lose proton from their acid –NH3+ <br />• see page 490 <br />o the structure and charge of an amino acid depends on the pH environment <br /> <br /> <br />• isoelectric pH: IpH; the pH region in which the in a given sample of an amino acid or a protein, there is an net equal number of positive and negative charges <br />o any point below the Ip there is a net + charge <br /> an acid soln. <br />o any point above the Ip there is a net – charge <br /> a basic soln. <br />o repulsive forces smallest at the Ip <br /> then the proteins tend to clump together and become insoluble as the groups interact and become bonded together <br /> proteins are least soluble at their Ip <br /> <br />• can be used as an effective tool for separating protein chains with identical or similar MW but different amino acid composition <br /> <br /> <br />Handedness <br /> <br />• chiral: having right or left handness, able to have two different mirror images <br /> <br />• achiral: the opposite of chiral; having no right or left handness and no non-superimposable mirror image <br />• not all things have handedness <br />• if have handedness have lack of symmetry <br /> <br /> -O - C = O O = C – O- <br /> | | <br />+H3N-C-H H - C – NH3+ <br /> | | <br /> CH3 CH3 <br /> <br /> L-alanine R-alanine <br /> <br />L  the amino groups points to the left <br />propane has a symmetry plane <br /> <br />What determines if a molecule is chiral? <br /> 1) can predict from structure of molecule <br /> 2) chiral compound have four different groups bond to central carbon. Can have more than one chiral <br />center in a compound <br /> <br /> <br />• the two mirror images of a chiral molecule like alanine are called enantiomers or optical isomers because of their effect on polarized light <br /> <br />• stereoisomers: isomers that have the same molecular formula but different spatial arrangements of their atoms <br /> <br />• shared properties of alanine enantiomers: <br /> mp <br /> density <br /> solubility <br /> Ip <br /> density <br /> <br />• differing properties of alanine enantiomers: <br /> opposite directions on polarized light <br /> react w/ other molecules <br /> odor <br /> taste <br /> toxicity <br /> drug activity <br /> <br /> <br />Primary Protein structure <br /> <br />• primary protein structure: is the sequence of a protein in which the amino acids are lined up end to end and in order, connected by peptide bonds <br />o the “R” groups are just substituents and do not contribute to the primary structure <br />o determines the secondary and tertiary structure of the protein <br /> that is the manner in which it twists, turns, and folds on itself to produce its final 3-D shape <br /> <br />• sequence is what allows the protein to carry out its job <br />o one specific order can do the job <br />o one AA change can affect how a protein behaves as in the case of sickle cell hemoglobin: <br /> Ingram and Pauling 1954 <br /> single amino acid substitution in the  chain <br /> valine is present in place of glutamine on position 6 of the  chain of a polypeptide chain 574 amino acid in length <br /> this substitution replaces a polar amino acid with a non polar amino acid <br />• which results in reduced the solubility of oxygenated hemoglobin <br />• this causes a “sticky” effect and causes a sickling effect when there is inadequate of oxygen <br />• occurs in the blood capillaries <br />• sickling can block the capillaries <br />• these cells are destroyed by the body defenses resulting in anemia <br /> <br /> <br />o in the case of human insulin which has two amino acid chains for a total of 51 AAs, the chains are connected by a disulfide bridge <br /> sequence determined by Sanger 1958 <br /> <br />o if you are an insulin dependent diabetic you might take insulin from the following sources below <br /> <br />o they are similar, but not as active as human insulin <br /> <br />o can be become allergic, due to an antigenic response to a foreign protein <br /> <br />o the chart below displays the four locations in which the substitute insulin differs from human insulin <br /> <br />A chain B chain <br /> <br />human -Thr-Ser-Ile- -Thr- <br />Bovine -Ala-Ser-Val- -Ala- <br />Hog -Thr-Ser-Ile- -Ala- <br />Sheep -Ala-Gly-Val- -Ala <br /> <br /> <br /> <br /> <br /> General information: <br /> <br />• note there is one N-terminal end <br /> <br />• note there is one C-terminal end <br /> <br />• N-terminal comes from the 5’ end of informational strand <br /> <br />• C-terminus comes from the 3’ end of that same informational strand <br /> <br />• this is a rigid planar unit between adjacent amino acids <br /> <br />• by convention the N-terminal is on the left <br /> <br />• by convention the C-terminal is on the right <br /> <br />• residue: any amino acid unit in a polypeptide <br /> <br />• a polypeptide is named by citing the amino acid residues in order starting at the N-terminal end using “yl” endings and the C-terminal end, ends in “ine” <br /> <br />• no matter how long the chain becomes, there is always only one N and one C terminal end <br /> <br />Note: some diabetics have not be successful with insulin <br /> produced by recombinant DNA techniques. They <br /> express the problem as not having enough of what <br /> is called hypoglycemic awareness <br /> <br /> Shape Determination Interactions <br /> <br />• w/o interactions between atoms in amino acid side chains or along the backbone, protein chains would also be in a random coil arrangement <br /> <br />• the essential structure-function relationship is predicated on the 3-D structure of the protein or enzyme <br /> <br />• Types of interactions: <br />o hydrogen bonds along the backbone: hydrogen bonds form when a hydrogen atom is attracted to another highly electronegative atoms that has an unshared pair of electrons: <br /> see figure 18.4 <br /> -NH- with –C=O <br /> between neighboring backbone segments <br /> results in helixes and pleated sheets <br /> creates rigid structure <br /> often involves adjacent atoms <br /> <br /> <br />• Hydrogen Bonds of R groups with Each Other or with Backbone Atoms <br />o see figure 18.4 <br />o stabilize a loop <br />o whenever AA side chains contain atoms which can form hydrogen bonds, such bonds can be connect nearby and distant amino acids: <br /> -NH- with –C=O <br /> -OH with –NH- <br /> -OH with –C=O <br />• phenol group with a carbonyl group <br /> <br /> <br />• Ionic_Attractions between R groups (salt bridges): <br />o see Figure 18.4 <br />o when there are ionized acidic and basic groups <br />o attraction of + and – charges <br /> can stabilize a loop <br />• a basic lysine with an acidic asparate <br />• amine group with a carboxylic acid group <br /> <br />• Hydrophobic Interactions Between R Groups <br />o see figure 18.4 <br />o weaker than hydrogen bonds <br />o acts over larger surface area <br /> net effect is to stabilized a loop <br />o non-polar hydrophobic chains cluster together in the same way oil drops cluster together <br />o typically found in center of a globular protein which is water free <br /> creates a water free pocket <br />• alanine and leucine <br />• benzene ring with an isopropyl group <br /> <br /> <br />• Covalent Sulfur-Sulfur Bonds; called a sulfur bridge <br />o see page 500 <br />o can stabilize a loop by oxidizing Rx <br />o can occur between two separate chains as in insulin <br />o under conditions of oxidation, two cysteine AA can react together to form a disulfide bond creating a loop <br />• insulin <br />o if two cysteines are in different chains, the chains can be linked together by disulfide bonds <br /> insulin also provides a good example <br /> <br /> <br />Secondary Structure of Proteins <br /> <br />• secondary structure: regular and repeating structural pattern created by hydrogen bonding between backbone atoms in neighboring segments of protein chains, so that certain patterns repeat themselves <br />o this is the steric relationship of the amino acid residues which are close to each other in the linear sequence, some are of a regular kind giving rise to a composition of periodic structure <br /> <br />• alpha helix: secondary protein structure in which a protein chain forms a right handed coil stabilized by hydrogen bonds between peptide groups along its backbone <br />o Pauling and Correy <br />o similar to a tightly coiled telephone wire cord <br />o similar to that of a spring <br /> shape maintained by numerous intramolecular hydrogen bonds that exist along its backbone <br /> found in DNA <br />o stabilized by –C= O (carbonyl) and –NH- (amide hydrogens four resides down along chain) <br /> <br /> <br /> <br />•  pleated sheet: secondary protein structure in which adjacent protein chains in the same or different molecules are held together in place by hydrogen bonds along the backbone <br />o be definition not quaternary <br />o Pauling and Correy <br />o orderly arrangement maintained by intermolecular hydrogen bonds to adjacent chains <br />o sheet tends to be fully extend, not tight coil as in alpha helix <br /> regular pattern of hydrogen bonds <br /> chains run can side by side to each other <br /> chain arranged in anti-parallel arrangement chain # 1 N-terminal ------ C-terminal <br /> chain # 2 C-terminal ------ N-terminal <br />o silk <br /> chains can also run parallel <br />o within the same chain could form a U shaped segment; intra-chain, this is called the β turn which creates a hair pin loop and then the pattern repeats of the rungs on the ladder repeats <br /> <br />See Figure 18.6 page 503 <br /> Protein chains lie side by side to each other <br /> alternating chains create anti parallel arrangement <br /> can stack as sheets <br /> inter-chain arrangement <br /> <br />random coils: protein configurations that do not exhibit a repeated pattern <br /> <br /> <br />Secondary Structure in Fibrous and Globular Proteins <br /> <br />• protein can also be classified in other ways: <br /> fibrous <br /> globular <br /> <br />• fibrous proteins: a tough, insoluble protein whose protein chains form fibers or sheets <br />o determined primarily by secondary structure <br />o mostly  keratin <br /> pairs of  helixes are twisted together into small fibrils, which are then used as a subunit to build larger bundles <br />o fibroin is mostly  pleated sheet <br /> <br /> <br />• another pattern which is classified as secondary structure is the triple helix of collagen <br />o third example of a periodic structure arrangement <br />o special arrangement of the primary structure which allows for three polypeptide chains to come together <br />o each strand is made of repetitive units that can be symbolize as Gly-X-Y <br />o every third amino acid is glycine <br />o glycine has a short “R” group which allows for close packing <br />o X is frequently proline <br />o Y is often hydroxyproline <br />o triple helix units together constitute what is called tropocollagen <br /> an association of triple helixes results in quaternary level or organization <br /> collagen is made up of many units of tropocollagen <br /> connective tissue of: <br />• bone <br />• cartilage <br />• tendons <br />• aorta <br />• skin <br /> <br />• globular proteins: a water soluble protein who chain is folded in a compact shape with hydrophilic groups on the outside <br />o tertiary, include levels of secondary structure <br />o when protein chains fold back on themselves: <br />o can result form  helixes and  pleated sheets <br />o see protein classification chart 18.4 page 504 <br /> <br />Tertiary Protein Structure <br /> <br />• tertiary protein structure: the way in which an entire protein chain is coiled and folded into a specific 3-D shape. <br /> depends primarily on interactions of amino acid side chains that are far apart along the same backbone <br /> determined by primary sequence <br /> maximum stability <br /> creates a native protein: a protein with the shape in which is exists naturally <br /> non-covalent and disulfide bonds can also govern tertiary structure <br /> <br />• proteins can also be classified in another way: <br /> simple: contains only AAs following hydrolysis <br /> conjugated: upon hydrolysis; <br />• AAs <br />• plus a non-protein non amino component <br />o the two together allows the protein to be active <br />• see table classification 18.5 page 506 <br /> <br />Quaternary Structure <br /> <br />• Quaternary Structure: the way in which two or more proteins chains aggregate to form a large order structure non-covalent interactions <br /> <br />• Hemoglobin: <br />o globular protein <br />o quaternary structure <br />o four subunits <br />o held together by hydrophobic attractions <br />o each  pair contains one heme unit <br /> <br />• collagen: <br />o fibrous protein <br />o found in bone <br />o found in dentine of teeth <br />o found in tendons <br />o basic unit is tropocollagen which is then intertwined with other tropocollagen units resulting <br /> crosslinking pattern which called quarter staggered arrangement <br />• units (tropocollagen) are not aligned end to end, but are staggered <br />• units are separated by a gap which are a nucleation for the growth of calcium crystals in bone <br />o facts about tropocollagen <br /> three chains wrapped around each other <br /> each chain is about 1000 AAs in length <br /> these chains are then cross linked and overlapped together: <br />• calcium hydroxyapatite fills in gaps of the cross linked structures <br /> <br />Chemical Properties of Proteins <br /> <br />• protein hydrolysis: <br />o reverse of protein formation <br />o peptide bonds are broken <br />o result is a pool of amino acids <br />o breaking down of primary structure <br /> HCl <br />• digestion of proteins in stomach and small intestine <br /> <br /> <br />• denaturation: the loss of secondary, tertiary, and quaternary protein structure due to the disruption of non-covalent interactions and/or disulfide bonds that leaves the peptide bonds intact of the primary structure <br />• the 3-D structure is really a delicate balance of non-covalent interactions <br />• change balance will change 3-D shape <br />• when 3-D shape disrupted, a random coil results <br />• when denatured, the net effect on the protein includes: <br />o chemical <br /> catalytic activity is often lost <br />o physical <br /> solubility is decreased <br />o biological <br /> function is lost <br /> <br /> <br /> <br />Agents which cause denaturation <br /> <br />• Heat: <br />o increase the kinetic energy of the protein <br />o there are weak side chain interactions which can be disrupted because of the increased thermal energy of vibration <br />o in general temperature above 50 or 60 degrees will denature most proteins: <br />• melt temperature <br /> <br />• Mechanical Action: <br />o caused by stretching <br />o this decreases solubility <br /> <br />• Detergents: <br />o surface acting agents <br />o disrupts hydrophobic interactions found in the protein chain <br /> <br />• Organic Chemicals: <br />o polar solvents such as acetone and alcohols <br />• competes for the hydrogen bonds found in the original 3 – D structure <br />• breaks up the internal hydrogen bonds <br />o this twists and unwinds the chain <br />o –HN- group forms hydrogen bonds with –C=O of an acetone molecule <br />o an –HN- form hydrogen bonds with HO- of an alcohol <br /> <br /> <br />• pH change: <br />o Excess hydrogen ions or hydroxyl groups interact with the basic or acidic side groups and disrupt the salt bridges creating their own acid/base relationships <br />o also disrupts hydrogen bonds <br />o exposure to strong acids and bases for a long period of time will result in the hydrolysis of the protein chain <br /> <br />• Inorganic salts <br />o PbCl2 <br />o AgCl <br />o HgCl2 <br />• reducing agents <br />o high concentrations of heavy metals can disrupt salt bridges <br />o bind w/ sulfur contain groups to create metal sulfides <br /> <br />• Oxidizing reagents: <br />o create sulfur bridges <br />o HNO3 <br /> <br />• Alaloidal reagents <br />o disrupt salt bridges <br />o disrupt hydrogen bonds <br /> <br /> <br />• if the changes in the structure is small, denaturation can be reversed and the protein can resume its secondary and tertiary structure and biological function <br /> <br />• in biological systems, certain proteins called chaperones help a newly synthesized polypeptide chain to assume the proper secondary and tertiary structure that are necessary for the functioning of that molecule and prevent foldings that are not biologically active <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108784062010470668?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1087421583450446052004-06-16T14:32:00.001-07:002004-06-16T14:33:03.453-07:00 Carbohydrates <br /> <br />Section: 22.1 <br /> <br />• carbohydrates: a member of a large class of naturally occurring polyhydroxy aldehydes or ketones <br /> name of compd. ends w/ the “ose” ending <br /> <br />• monosaccharides: a carbohydrate that can not be broken down into smaller units by hydrolysis with aqueous acid <br />o typically three to seven carbons in length <br /> glucose: pentylhydroxylhexanal <br /> fructose: pentylhydroxylhexanone <br /> galactose: penthylhyroxylhexanal <br /> page 630 <br /> <br />• disaccharide: a carbohydrate, which yields two monosaccharides on hydrolysis, identical or different. Bonds are really ether like linkages (glycosidic bonds) page 647 - 649 <br />o held together by a glycosidic bond or also called acetal bond <br /> lactose <br /> maltose <br /> sucrose <br /> <br />• polysaccharides: a carbohydrate that is composed of many monosaccharides bonded together. This is really a polymer of many monosaccharides put together end to end. Really a polymer of monosaccharides. Monomer composition cab be identical or different, and if different order determines the type polysaccharide <br />o complex carbohydrates: page 653 <br /> glycogen: animal <br /> cellulose: plant: fiber <br /> amylose: plant <br /> amylopectin: plant <br /> <br /> <br />• aldose: monosaccharide which contains an aldehyde functional group: page 630 <br /> <br />• ketose: a monosaccharide which contains a ketone functional group <br /> <br /> <br />Naming and Examples of monosaccharides <br /> <br />• the number of carbons is specified by multiplicative prefixes identical to that in naming other compds <br /> <br />• see page: 630 <br /> <br />• can you find the aldehyde functional group? <br /> <br />• can you find the ketone functional group? <br /> <br /> <br /> <br />Section 22.2 Handedness of Carbohydrates <br /> <br />• the simplest of the carbohydrates is the three carbon compd. Glyceraldehydes: <br />o page 631 <br />• there exists two forms: <br />o D-glyceraldehyde <br />o L-glyceraldehyde <br />• these compds exist chiral character <br />o meaning lack of plane of symmetry <br />o they are mirror images of each other <br />o same chemical properties <br />o all physical properties are the same except their ability to rotate a plane of polarized light <br />o there are called optical isomers <br />o the measurement of optical rotations is accomplished by a device called a polarimeter <br />o one will rotate light to the right and the other will rotate light to the left <br />o this compd. w/ one chiral center can only have two optical isomers <br />o if there are more chiral centers, then there are more optical isomers possibilities <br />o if you have 2 chiral centers, then you can have four optical isomers <br /> two optical isomer pairs <br />o thus there is a D and L erythrose and a D and L threose <br />o however, erythrose and threose are stereoisomerisms <br /> stereoisomers: some formula and connections but different spatial arrangement <br /> diastereomers: stereoisomers that non mirror images of each other <br /> <br />Section 22.3 Fisher Projections <br /> <br />D-sugars: monosaccharides with the OH group on the chiral atom farthest from the carbonyl group pointing to the right in a <br /> <br />Fisher projection. The representation “dextro” is derived from the fact that the OH group points to the right <br /> <br />L-sugar: monosaccharide with the OH group on the chiral atom farthest from the carbonyl group pointing to the left in a Fisher projection. The representation “levo” is derived from the fact the OH group points to the left <br /> <br /> <br />• see page 635 <br /> <br />In a Fisher projection, the carbonyl group of the ketone or the aldehyde is always placed at the top of the projection <br /> <br />glyceraldehyde is the simplest of the monosaccharides <br /> <br /> this means that the OH and the H groups pointing to the left and the <br />right of the chiral atoms are projecting out of the paper and those above and below the chiral centers are projecting into the paper <br /> <br /> see page 633 again <br /> <br /> note in the D sugar form the OH group projects out of the paper <br /> and to the right <br /> note in the L sugar form the OH group projects out of the paper and <br /> to the left <br /> <br /> <br />22.4 Structure of Glucose and others <br /> <br />• sometimes call dextrose or blood sugar <br />• source of energy for almost all living organisms <br />• stored as a polymer as starch in plants and glycogen in animals <br />• hemiacetal forms from the internal condensation of an aldehyde group and an alcohol group of that sugar <br />• internal hemiacetal formation is possible <br />• the C1 and C5 carbons condense to form a six member ring which has an oxygen in the ring instead of a carbon <br />• see figure 22.3 page 637 <br />• OH groups pointing left point up in the cyclic structure and those which point to the right, point down <br />• the hemiacetal carbon is always bonded to two oxygen atoms <br />• this means that the carbon is chiral <br />• this creates alpha and beta anomers <br />• in the beta form the OH group points up and in the alpha form the OH group points down <br />• anomers: cyclic sugars that differ only in the positions of the OH on the hemiacetal carbon; the alpha form has the OH group on the opposite side of the –CH2OH; the beta form has the –OH group on the same side as the –CH2OH <br />• anomeric carbon: the hemiacetal C atom in the cyclic sugar, the C atom bonded to an –OH group and an O in the ring <br />o in aldoses it is carbon # 1 <br />o in ketone based sugars it is carbon # 2 page 643 <br />• mutarotation: change in rotation of plane polarized light resulting form the equilibrium between cyclic anomers and the open chain form of a sugar <br />• see page 638 for review: KNOW! <br />• Bullet points page 639 <br /> <br /> <br />Section 22.5: Important Monosaccharides <br /> <br />• the monosaccharides w/ their many hydroxyl groups which permit hydrogen bonding between other monosaccharides are generally high melting, white crystalline solids <br />• w/ many opportunities for hydrogen bonding, they have high solubility in water and are insoluble in non-polar solvents <br />• most are sweet in taste and digestible as an energy source <br />• those of interest include: <br />o glyceraldehyde <br />o fructose <br />o aldohexoses <br />o aldopentoses <br />• most are in the D-family <br />• Glucose: <br />o most important of the carbohydrate of human metabolism <br />o one of the final products of carbohydrate digestion <br />o provides acetyl groups in the form of acetyl-SCoA for the Krebs’ Cycle <br />o hormones insulin and glucagon maintain proper glucose levels in the blood <br />• Galactose: <br />o component of the digestion of lactose <br />o aldohexose (see page 648) <br />o identical in arrangement of the carbons and hydroxyl groups in order, but orientation of the OH- group at position turned and opposed to glucose where it is turned down <br />o the body converts galactose to glucose <br />o galactose can be made from glucose to provide lactose for breast milk <br />o galactosemia: genetic disorder which the individual cannot process galactose, its build up may cause mental retardation, liver failure, and cataracts <br /> <br /> <br />• Fructose: <br />o see page 643 <br />o ketohexose <br />o part of the glycolysis cycle <br />o six carbon sugar <br />o because of the presence of the ketone functional group and through internal condensation with carbon # 5, a five member ring results <br />o there are also α and β anomers <br />o sweeter then sucrose <br /> <br />• Ribose and 2-Deoxyribose <br />o see page 644 <br />o both are five carbon aldehyde sugars <br />o found in many aspects of biological chemistry, especially DNA, RNA, and cyclic AMP <br /> <br />22.6 Reactions of Monosaccharides <br /> <br />• Reactions w/ oxidizing agents: Reducing sugars by definition <br />o aldehydes can be oxidized to carboxylic acids, but that reaction applies only to open chained form of the aldose monosaccharides <br />o if you have a given sample, the open chain will continue to react with the oxidizing agent, the equilibrium will shift, until all of the cyclic forms are consumed <br />o any carbohydrate that reacts w/ a reducing agent is called a reducing sugar by definition <br />o a ketose also behave as reducing sugar in basic solution such as Benedicts’ because of a keto-enol tautomeric shift, that is the ketone is converted to an aldehyde <br />o this aldehyde then can undergo oxidation <br />o in basic solns., all monosaccharides of either ketose or aldose origin behave as reducing sugars <br /> <br />• Reactions with Alcohols: <br />o an alcohols is a hemiacetal which can react with other alcohols to make a acetal <br />o a acetal has two OR groups bonded to the same carbon <br />o the class of compounds which reacts when a cyclic hemiacetal reacts together is called a glycoside: <br /> a cyclic acetal formed by the Rx of a monosaccharide with an alcohol w/ accompanied by the release of water, a condensation reaction <br />• the bond which o=is formed by this condensation reaction is called a glycosidic bond, by definition, the anomeric carbon must be involved in that bond <br />• when two monosaccharides are combined, the anomeric carbon of one carbon is reacted w/ the –OH of another monosaccharide <br /> <br />22.7 Disaccharides: <br /> <br />• when you have a disaccharide, the bond can also be α or β <br />• in the example on page 647 there is representation of an α and β bond types. These are stereoisomers of each other <br />• Maltose: <br />o malt sugar <br />o two α D-glucose molecules are linked in an alpha configuration <br />o note that carbons 1 and 4 are involved, hence name is called α 1-4 glycosidic bond <br />• Lactose: <br />o β-D-Galactose <br />o β-D-Glucose <br />o β-1,4 glycosidic bond <br />o age increases risk of lactose intolerance <br /> <br /> <br />• Sucrose: <br />o table sugar <br />o hydrolysis of sucrose produces: <br /> α-D-glucose <br /> β-D-fructose <br />• called invert sugar <br />• non reducing sugar because the anomeric carbons are linked together <br />• bond type is a 1,2 anomeric link <br />• can not ID as α or β link because both anomeric carbons are joined together <br />• only common disaccharide which is not a reducing sugar, a good ID for lab when trying to distinguish between two disaccharides <br /> <br />22.8 Variation on Carbohydrate Theme <br /> <br />• monosaccharides w/ modified functional groups are found and have many important structural applications, see page 651 <br />• Chitin: <br />o structural polymer <br />o insect shells <br />o N-acetyl-D-glucosoamine <br />• Connective tissue Polysaccharides: <br />o protein fibers are embedded in a matrix of un-branched polysaccharides (mucopolysaccharides) <br />o these gel like polymers behave as lubricants <br />o repeating unit of two modified monosaccharides <br /> Hyaluronate: 25K units in length <br /> rigid material <br /> holds water <br /> synovial fluid <br /> <br /> <br />• Chrondroitin-6-sulfate: <br />o tendons and cartilage <br />o linked to proteins <br />o dietary supplements <br />• Heparin: <br />o another polymer <br />o anticoagulant <br />o various composition contain sulfate groups <br />o has many negative charges to bond tightly to blood clotting factors <br />• Glycoproteins: <br />o a protein that’s a short carbohydrate chain <br />o carbohydrate is connected to the protein by a glycosidic bond between the anomeric carbon and a side chain of the protein, the bond is of two types, a C-N glycosidic bond or C-O glycosidic bond to an oxygen atom of a side chained hydroxyl group <br />o major function is cell surface markers <br />o important in blood group identification <br />o the protein portion is buried in the cell membrane and the carbohydrate portion extends above the surface of the cell membrane <br />o see page 654 <br />o note the common N-acetyl-D-glucose amine bade for all three blood groups <br />o L-fucose is found in all three blood groups <br />o N-acetyl-D-galactose amine is found only in blood group A <br />o D-galactose is found only in blood group B <br />o if you are an AB individual, then you have the separate glycoproteins which contain N-acetyl-galactose amine and galactose as your markers <br /> <br /> <br />22.9 Important Polysaccharides <br /> <br />• Cellulose: <br />o see page 653 <br />o fibrous structure that provides support in plants <br />o made up of β-D-glucose units in repeated fashion <br />o links are called β 1-4 glycosidic bonds <br />o see anti-parallel arrangement <br />o hydrogen bonding holds the structure together <br />o we as humans can not digest cellulose because we lack the enzyme β-cellulase <br /> <br />• Starch: <br />o General properties <br /> polymer of α-D-glucose <br /> joined by α 1-4 glycosidic links <br /> fully digestible because α-amylase <br /> found only in plant material: <br />• beans <br />• potato <br />• wheat <br />• rice <br />o amylose: page 656 <br /> 20% of the total plant starch <br /> somewhat soluble in hot water <br /> several hundred to 1000 units of α-D-glucose linked together by α 1-4 glycosidic bonds <br /> coils in helical arrangement, not anti-parallel sheets <br /> w/o branching <br /> <br /> <br />o amylopectin: page 656 <br /> 80 % of the starch <br /> identical monomer construction <br /> up to 100,000 monomer units <br /> α 1-6 branch to an α-D-glucose occurs approximately on each 25th α-D-glucose unit, branches can also be 100,000 units long <br /> digested in small intestine by α-amylase which catalyzes the α 1-4 links <br /> <br />o Glycogen: <br /> animal starch <br /> energy storage in the liver and muscles <br /> when used as energy source, the glucose is converted to glucose-6-phosphate for glycolysis <br /> branch points as in amylopectin but every 10 units <br /> size is 1,000,000 units <br /> readily mobilized form of glucose storage <br /> designed to increase the amount of glucose that is immediately available following between meals <br /> important for blood glucose levels and regulation <br /> reservoir of glucose for strenuous muscle activity <br /> the α 1-6 branch is broken down by a debranching enzyme called α 1-6 gluosidase which is found in the liver <br /> other debrancing enzymes, collectively called pancreatins complete the activity in the small intestine <br /> <br /> <br /><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7191541-108742158345044605?l=lmlechko.blogspot.com' alt='' /></div>LMLechkohttp://www.blogger.com/profile/16873345389290956299noreply@blogger.com0tag:blogger.com,1999:blog-7191541.post-1087421544613182462004-06-16T14:32:00.000-07:002004-06-16T14:32:24.613-07:00 Carbohydrates <br /> <br />Section: 22.1 <br /> <br />• carbohydrates: a member of a large class of naturally occurring polyhydroxy aldehydes or ketones <br /> name of compd. ends w/ the “ose” ending <br /> <br />• monosaccharides: a carbohydrate that can not be broken down into smaller units by hydrolysis with aqueous acid <br />o typically three to seven carbons in length <br /> glucose: pentylhydroxylhexanal <br /> fructose: pentylhydroxylhexanone <br /> galactose: penthylhyroxylhexanal <br /> page 630 <br /> <br />• disaccharide: a carbohydrate, which yields two monosaccharides on hydrolysis, identical or different. Bonds are really ether like linkages (glycosidic bonds) page 647 - 649 <br />o held together by a glycosidic bond or also called acetal bond <br /> lactose <br /> maltose <br /> sucrose <br /> <br />• polysaccharides: a carbohydrate that is composed of many monosaccharides bonded together. This is really a polymer of many monosaccharides put together end to end. Really a polymer of monosaccharides. Monomer composition cab be identical or different, and if different order determines the type polysaccharide <br />o complex carbohydrates: page 653 <br /> glycogen: animal <br /> cellulose: plant: fiber <br /> amylose: plant <br /> amylopectin: plant <br /> <br /> <br />• aldose: monosaccharide which contains an aldehyde functional group: page 630 <br /> <br />• ketose: a monosaccharide which contains a ketone functional group <br /> <br /> <br />Naming and Examples of monosaccharides <br /> <br />• the number of carbons is specified by multiplicative prefixes identical to that in naming other compds <br /> <br />• see page: 630 <br /> <br />• can you find the aldehyde functional group? <br /> <br />• can you find the ketone functional group? <br /> <br /> <br /> <br />Section 22.2 Handedness of Carbohydrates <br /> <br />• the simplest of the carbohydrates is the three carbon compd. Glyceraldehydes: <br />o page 631 <br />• there exists two forms: <br />o D-glyceraldehyde <br />o L-glyceraldehyde <br />• these compds exist chiral character <br />o meaning lack of plane of symmetry <br />o they are mirror images of each other <br />o same chemical properties <br />o all physical properties are the same except their ability to rotate a plane of polarized light <br />o there are called optical isomers <br />o the measurement of optical rotations is accomplished by a device called a polarimeter <br />o one will rotate light to the right and the other will rotate light to the left <br />o this compd. w/ one chiral center can only have two optical isomers <br />o if there are more chiral centers, then there are more optical isomers possibilities <br />o if you have 2 chiral centers, then you can have four optical isomers <br /> two optical isomer pairs <br />o thus there is a D and L erythrose and a D and L threose <br />o however, erythrose and threose are stereoisomerisms <br /> stereoisomers: some formula and connections but different spatial arrangement <br /> diastereomers: stereoisomers that non mirror images of each other <br /> <br />Section 22.3 Fisher Projections <br /> <br />D-sugars: monosaccharides with the OH group on the chiral atom farthest from the carbonyl group pointing to the right in a <br /> <br />Fisher projection. The representation “dextro” is derived from the fact that the OH group points to the right <br /> <br />L-sugar: monosaccharide with the OH group on the chiral atom farthest from the carbonyl group pointing to the left in a Fisher projection. The representation “levo” is derived from the fact the OH group points to the left <br /> <br /> <br />• see page 635 <br /> <br />In a Fisher projection, the carbonyl group of the ketone or the aldehyde is always placed at the top of the projection <br /> <br />glyceraldehyde is the simplest of the monosaccharides <br /> <br /> this means that the OH and the H groups pointing to the left and the <br />right of the chiral atoms are projecting out of the paper and those above and below the chiral centers are projecting into the paper <br /> <br /> see page 633 again <br /> <br /> note in the D sugar form the OH group projects out of the paper <br /> and to the right <br /> note in the L sugar form the OH group projects out of the paper and <br /> to the left <br /> <br /> <br />22.4 Structure of Glucose and others <br /> <br />• sometimes call dextrose or blood sugar <br />• source of energy for almost all living organisms <br />• stored as a polymer as starch in plants and glycogen in animals <br />• hemiacetal forms from the internal condensation of an aldehyde group and an alcohol group of that sugar <br />• internal hemiacetal formation is possible <br />• the C1 and C5 carbons condense to form a six member ring which has an oxygen in the ring instead of a carbon <br />• see figure 22.3 page 637 <br />• OH groups pointing left point up in the cyclic structure and those which point to the right, point down <br />• the hemiacetal carbon is always bonded to two oxygen atoms <br />• this means that the carbon is chiral <br />• this creates alpha and beta anomers <br />• in the beta form the OH group points up and in the alpha form the OH group points down <br />• anomers: cyclic sugars that differ only in the positions of the OH on the hemiacetal carbon; the alpha form has the OH group on the opposite side of the –CH2OH; the beta form has the –OH group on the same side as the –CH2OH <br />• anomeric carbon: the hemiacetal C atom in the cyclic sugar, the C atom bonded to an –OH group and an O in the ring <br />o in aldoses it is carbon # 1 <br />o in ketone based sugars it is carbon # 2 page 643 <br />• mutarotation: change in rotation of plane polarized light resulting form the equilibrium between cyclic anomers and the open chain form of a sugar <br />• see page 638 for review: KNOW! <br />• Bullet points page 639 <br /> <br /> <br />Section 22.5: Important Monosaccharides <br /> <br />• the monosaccharides w/ their many hydroxyl groups which permit hydrogen bonding between other monosaccharides are generally high melting, white crystalline solids <br />• w/ many opportunities for hydrogen bonding, they have high solubility in water and are insoluble in non-polar solvents <br />• most are sweet in taste and digestible as an energy source <br />• those of interest include: <br />o glyceraldehyde <br />o fructose <br />o aldohexoses <br />o aldopentoses <br />• most are in the D-family <br />• Glucose: <br />o most important of the carbohydrate of human metabolism <br />o one of the final products of carbohydrate digestion <br />o provides acetyl groups in the form of acetyl-SCoA for the Krebs’ Cycle <br />o hormones insulin and glucagon maintain proper glucose levels in the blood <br />• Galactose: <br />o component of the digestion of lactose <br />o aldohexose (see page 648) <br />o identical in arrangement of the carbons and hydroxyl groups in order, but orientation of the OH- group at position turned and opposed to glucose where it is turned down <br />o the body converts galactose to glucose <br />o galactose can be made from glucose to provide lactose for breast milk <br />o galactosemia: genetic disorder which the individual cannot process galactose, its build up may cause mental retardation, liver failure, and cataracts <br /> <br /> <br />• Fructose: <br />o see page 643 <br />o ketohexose <br />o part of the glycolysis cycle <br />o six carbon sugar <br />o because of the presence of the ketone functional group and through internal condensation with carbon # 5, a five member ring results <br />o there are also α and β anomers <br />o sweeter then sucrose <br /> <br />• Ribose and 2-Deoxyribose <br />o see page 644 <br />o both are five carbon aldehyde sugars <br />o found in many aspects of biological chemistry, especially DNA, RNA, and cyclic AMP <br /> <br />22.6 Reactions of Monosaccharides <br /> <br />• Reactions w/ oxidizing agents: Reducing sugars by definition <br />o aldehydes can be oxidized to carboxylic acids, but that reaction applies only to open chained form of the aldose monosaccharides <br />o if you have a given sample, the open chain will continue to react with the oxidizing agent, the equilibrium will shift, until all of the cyclic forms are consumed <br />o any carbohydrate that reacts w/ a reducing agent is called a reducing sugar by definition <br />o a ketose also behave as reducing sugar in basic solution such as Benedicts’ because of a keto-enol tautomeric shift, that is the ketone is converted to an aldehyde <br />o this aldehyde then can undergo oxidation <br />o in basic solns., all monosaccharides of either ketose or aldose origin behave as reducing sugars <br /> <br />• Reactions with Alcohols: <br />o an alcohols is a hemiacetal which can react with other alcohols to make a acetal <br />o a acetal has two OR groups bonded to the same carbon <br />o the class of compounds which reacts when a cyclic hemiacetal reacts together is called a glycoside: <br /> a cyclic acetal formed by the Rx of a monosaccharide with an alcohol w/ accompanied by the release of water, a condensation reaction <br />• the bond which o=is formed by this condensation reaction is called a glycosidic bond, by definition, the anomeric carbon must be involved in that bond <br />• when two monosaccharides are combined, the anomeric carbon of one carbon is reacted w/ the –OH of another monosaccharide <br /> <br />22.7 Disaccharides: <br /> <br />• when you have a disaccharide, the bond can also be α or β <br />• in the example on page 647 there is representation of an α and β bond types. These are stereoisomers of each other <br />• Maltose: <br />o malt sugar <br />o two α D-glucose molecules are linked in an alpha configuration <br />o note that carbons 1 and 4 are involved, hence name is called α 1-4 glycosidic bond <br />• Lactose: <br />o β-D-Galactose <br />o β-D-Glucose <br />o β-1,4 glycosidic bond <br />o age increases risk of lactose intolerance <br /> <br /> <br />• Sucrose: <br />o table sugar <br />o hydrolysis of sucrose produces: <br /> α-D-glucose <br /> β-D-fructose <br />• called invert sugar <br />• non reducing sugar because the anomeric carbons are linked together <br />• bond type is a 1,2 anomeric link <br />• can not ID as α or β link because both anomeric carbons are joined together <br />• only common disaccharide which is not a reducing sugar, a good ID for lab when trying to distinguish between two disaccharides <br /> <br />22.8 Variation on Carbohydrate Theme <br /> <br />• monosaccharides w/ modified functional groups are found and have many important structural applications, see page 651 <br />• Chitin: <br />o structural polymer <br />o insect shells <br />o N-acetyl-D-glucosoamine <br />• Connective tissue Polysaccharides: <br />o protein fibers are embedded in a matrix of un-branched polysaccharides (mucopolysaccharides) <br />o these gel like polymers behave as lubricants <br />o repeating unit of two modified monosaccharides <br /> Hyaluronate: 25K units in length <br /> rigid material <br /> holds water <br /> synovial fluid <br /> <br /> <br />• Chrondroitin-6-sulfate: <br />o tendons and cartilage <br />o linked to proteins <br />o dietary supplements <br />• Heparin: <br />o another polymer <br />o anticoagulant <br />o various composition contain sulfate groups <br />o has many negative charges to bond tightly to blood clotting factors <br />• Glycoproteins: <br />o a protein that’s a short carbohydrate chain <br />o carbohydrate is connected to the protein by a glycosidic bond between the anomeric carbon and a side chain of the protein, the bond is of two types, a C-N glycos