Notes for Biology

Biology 1: The Ce Parts of Cell Cytoskeleton Nucleoid Region: DNA region in prokaryotes. Microfilaments: Actin Nucleolus: Makes ribosomes. Sits in nucleus, no membrane. Peroxisomes: Collect and break down material. Microtubules: Tubulin Intermediate Filaments: Keratin = Vimentin; Desmin = Lamin Rough ER: Accept mRNA to make proteins. Smooth ER: Detox & make lipids. Golgi Apparatus: Modify / distribute proteins. Only in eukaryotes. Vesicular Transport COPII ® forward COPI ¬ return Cisternal Maturation Vesicles travel in retrograde New Cis made Cis/Medial/Trans/Exit Peroxisomes: Collect and break down material. Centrioles: 9 groups of microtubules, pull chromosomes apart. Lysosomes: Demo & Recycling center. Made by Golgi. Single membrane. Plasmids: In prokaryotes. Carry DNA not necessary for survival. Tissues Epithelia: Parenchyma (functional parts of organ). Simple: One layer. Stratified: Multiple layers. Pseudostratified: One layer (looks mult, but really just 1). Cuboidal: Cube shape. Columnar: Long and narrow. Squamous: Flat, scale-like. Connective: Stroma (support, extracellular matrix). Bone, cartilage, tendon, blood. Genetic Recombination Bacteria Obligate Aerobe: Requires O2. Bacilli Rod Cocci Sphere Spirilla Spiral Obligate Anaerobe: Dies in O2. Facultative Anaerobe: Toggle between Aerobic / Anaerobic. Aerotolerant Anaerobe: Does not use O2 but tolerates it. Transformation: Gets genetic info from environment. Conjugation: Transfer of genetic info via conjugation bridge. F+ ® F- or Hfr ® recipient Transduction: Transfer using bacteriophage. Transposons: Genetic info that can insert/remove themselves. Gram + is PURPLE, THICK peptidoglycan/lipoteichoic acid cell wall. Gram – is PINK-RED, THIN peptidoglycan cell wall & an outer membrane. Bacteriophage Eukaryote vs. Prokaryote Eukaryote Prokaryote ETC in mitochondria ETC in cell membrane Large ribosomes Small ribosomes Reproduce via mitosis Reproduce via binary fission Head with DNA or RNA Viruses Collar Sheath Plasmids carry DNA material. May have virulence factors. Plasmids that integrate into genome are Episomes Miscellaneous Prions: Infectious proteins. Trigger misfolding. a-helical ® b-pleated sheets. ¯Solubility. Viroid: Plant pathogens. Capsid: Protein Coat. Envelope: Some have lipid envelope. Base Plate Tail Fibers Virion: Individual virus particles. Bacteriophage: Bacteria virus. Tail sheath injects DNA / RNA. Viral Genome: May be DNA or RNA. Single or double stranded. If Single Strand: Positive Sense: Can be translated by host cell. Negative Sense: RNA replicase must synthesize a complimentary strand, which can then be translated. Retrovirus: Single stranded RNA. Reverse transcriptase needed to make DNA. Bacteriophage Lytic: Virions made until cell lyses. Life Cycles: Lysogenic: Virus integrates into genome as provirus or prophage. Goes dormant until stress activates it. Biology 2: Reproductio Cell Cycle Mitosis G1: Make mRNA and proteins to prep for mitosis Prophase: DNA condenses. Centrioles migrate to opposite poles and microtubules form. Nuclear envelope disappears. G0: A cell will enter G0 if it DOES NOT need to divide G1 Checkpoint: Cell decides if it should divide. P53 in charge - PMAT - Ploidy of 2n throughout Metaphase: “Meet in the middle”. Chromosomes meet in middle. Anaphase: “Apart”. Sister chromatids separate and move to opposite poles. S: DNA replicated G2: Cell growth. Make organelles Telophase: Chromosomes decondense. Nuclear membrane forms. Cytokinesis occurs. G2 Checkpoint: Check cell size & organelles M: Mitosis and cytokinesis Meiosis - PMAT x 2 Nondisjunction: When sister chromatids don’t separate properly during anaphase. Results in aneuploidy. Prophase I: Chromosomes condense, nuclear membrane dissolves, homologous chromosomes form bivalents, crossing over occurs. Growth Signals Positive Growth Signals: 1) 2) 3) 4) Negative Growth Signals: 1) 2) 3) CDK + Cyclin create a complex Phosphorylate Rb to Rb + P Rb changes shape, releases E2F Cell division continues CDK inhibitors block phosphorylation of Rb So, E2F stays attached Cell cycle halts Sex Chromosomes Sex determined by 23rd pair of chromosomes. XX = female. XY = Male. X-Linked Disorders: Males express, females can be carriers Y-Chromosome: Little genetic info. SRY gene = “Sorry you’re a male” Metaphase I: Spindle fibers from opposing centrosomes connect to bivalents (at centromeres) and align them along the middle of the cell. Anaphase I: Homologous pairs move to opposite poles of the cell. This is disjunction and it accounts for the Law of Segregation. Telophase I: Chromosomes decondense, nuclear membrane MAY reform, cell divides (cytokinesis), forms two haploid daughter cells of unequal sizes. Prophase II: Chromosomes condense, nuclear membrane dissolves, centrosomes move to opposite poles (perpendicular to before). Metaphase II: Spindle fibers from opposing centrosomes attach to chromosomes (at centromere) and align them along the cell equator. Anaphase II: Spindle fibers contract and separate the sister chromatids, chromatids (now called chromosomes) move to opposite poles. Telophase II: Chromosomes decondense, nuclear membrane reforms, cells divide (cytokinesis) to form four haploid daughter cells. Male Reproductive System Semen: Sperm + seminal fluid. Bulbourethral Glands: Makes viscous fluid to clean out urethra. SEVE(N) UP sperm pathway mnemonic Seminiferous tubules: Site of spermatogenesis. Nourished by Sertoli Cells. Epididymis: Stores sperm. Sperm gain motility. Vans deferens: Raise / lower testes. Ejaculatory duct: Urethra: Meiosis Diagram Seminal Vesicles & Make alkaline fluid to help sperm survive acidic Prostate Gland: environment of female reproductive tract. Penis: The Menstrual Cycle Female Reproductive System Ovaries: Have follicles that produce ova. Controlled by FSH and LH. Oogenesis: Production of female gametes. Estrogen: Response to FSH. Develops rep tract, thickens uterine wall. Progesterone: Response to LH. Maintains / protects endometrium. “Estrogen establishes; progesterone protects the endometrium”. Pathway: Egg ® peritoneal sac ® fallopian tube / oviduct Gonadotropin-Releasing Hormone (GnRH) FSH: Follicle Stimulating Hormone. Males: Triggers spermatogenesis, stimulates Sertoli Cells. Females: Stimulates development of ovarian follicles. LH: Luteinizing Hormone. Males: Causes interstitial cells to make testosterone. Females: Induces ovulation. Biology 3: Embryogenesis and Developmen 1 chorionic villi Fertilization placenta yolk sac Occurs in the Ampulla of fallopian tube. Sperm’s Acrosomal enzymes penetrate corona radiate & zona pellucia. Acrosomal enzymes inject pronucleus. Cortical reaction releases Ca2+ which depolarizes ovum membrane and makes it impenetrable. uterine lining umbilical cord chorionic cavity amnion 2 Morula amniontic fluid ¥ Early. Solid mass of cells 3 chorion uterine cavity Blastula internal os ¥ Implants in endometrial lining ¥ Fluid filled blastocoel ¥ Trophoblast ® Chorion / placenta ¥ Inner Cell Mass ® Organism 4 Gastrulation External os vaginal canal - Archenteron leads to blastopore Ectoderm: Nervous system, skin, hair, nails, mouth, anus. “Atract-oderm”: Skin, hair are things people are attracted to. Mesoderm: Muscoskeleton, circulatory system, gonads, adrenal cortex. “Move-oderm”: Involved in moving things such as muscles, RBC, steroids. Endoderm: Endocrine glands, GI tract, respiratory tract, bronchi, bladder, stomach. “In-doderm”: Things that are inside. 5 cervix Twins Fraternal = dizygotic Identical = monozygotic Cell Specialization Determination: Cell commits to becoming a certain type of cell Differentiation: Follows determination. Selectively transcribe genes appropriate for cell’s specific function Neurulation Mesoderm develops a Notochord. Notochord induces Ectoderm. Ectoderm ® Neural folds ® Neural tube ¯ ¯ Neural crest cells Central nervous system ¯ Peripheral nervous system Induction Group of cells influence the fate of nearby cells. Mediated by inducers, which are commonly growth factors. Cell Signaling Stem Cells Totipotent: “Total”, can be any type of cell Pluripotent: Can be any cell except those found in placental structures Paracrine Autocrine Multipotent: More specialized. Can be multiple types of cells *Adult stem cells are multipotent and require treatment w/ transcription factors Fetal Circulation Juxtacrine Endocrine Fetal Hemoglobin (HbF): #O2 affinity than HbA O2 and CO2 exchange via diffusion Fetal Shunts Umbilical Artery, − O2 PLACENTA Umbilical Vein, + O2 Skip Lungs: Foramen ovule: R atrium ® L atrium Ductus Arteriousus: Pulmonary artery ® Aorta Skip Liver: Umbilical vein ® inferior vena cava Biology 4: Nervous System dendrites Neurons nerve terminals Afferent: Ascend spinal cord node of ranvier Interneurons: Between other neurons (saltatory conduction) cell Body Efferent: Exit spinal cord (soma) Summations Temporal: Same space / Different time Spatial: Different space / Same time axon Schwann cell (PNS) Oligodendrocyte (CNS) myelin sheath Action Potential (faster) nucleus Astrocytes: Blood-brain barrier. Controls solutes moving from bloodstream ® nervous tissue. K+ out ation Repolariz Na+ in Depo lari za tion Glial Cells Ependymal Cells: The barrier between cerebrospinal fluid and interstitial fluid of the CNS. Microglia: Digest waste in CNS. Schwann Cells: PNS, makes myelin. Oligodendrocytes: CNS, makes myelin. Na+ K+ / Pump 3 Na+ out / 2 K+ in White / Grey Matter White Matter: Myelinated sheaths. Grey Matter: Cell bodies and dendrites. Unmyelinated. Brain: White deep / Grey outer Synapse Spinal Cord: Grey deep / White outer Reflex Arcs Monosynaptic: Sensory neuron ® motor neuron Polysynaptic: Sensory ® interneuron ® motor Central Nervous System - Brain & Spinal Cord Peripheral Nervous System Somatic Voluntary Sensory: Afferent Motor: Efferent Autonomic Sympathetic Neurotransmitter removed from synaptic cleft via either: ¥ Breakdown by enzymes ¥ Reuptake ¥ Diffusion out of cleft Parasympathetic Fight / Flight Relax bronchi Blood to locomotion ¯Peristalsis Rest / Digest Reduce bronchi Conserve energy #Peristalsis Neurotransmitters: Preganglionic: Acetylcholine Postganglionic: Epi / Norepi Neurotransmitters: Preganglionic: Acetylcholine Postganglionic: Acetylcholine Biology 5: Endocrine System Peptide Hormones G-Protein Coupled Receptor (GPCR) Made of amino acids 1) 2) 3) 4) Cleaved from larger polypeptide Golgi modifies & activates hormone Put in vesicles released via exocytosis Polar – cannot pass through membrane, so uses extracellular receptor like GPCR Common 2nd messengers: cAMP, Ca2+, IP3 Notes: Epinephrine is a ligand 1st messenger. At the end of the GPCR process, Phosphodiesterase deactivates cAMP and GTP hydrolyzed back to GDP. Ex: Insulin Steroid Hormones ¥ ¥ ¥ ¥ ¥ Made in Gonads & Adrenal Cortex, from Cholesterol Don’t dissolve, must be carried by proteins Non-polar, so CAN pass through membrane They activate nuclear receptors Direct action on DNA Direct vs. Tropic Hormones Direct Hormones: Act directly on target tissue/organ. Ex: Insulin. Ex: Estrogen / Testosterone / Cortisol Tropic Hormones: Require an intermediary. They only affect other endocrine tissues. Ex: GnRH and LH are both tropic. Amino Acid-Derivative Hormones Diabetes Share traits from both peptide & steroid hormones Type 1: No insulin, so glucose is not able to enter cells. Ex: Catecholamines use GPCR, Thyroxine bind intracellularly Type 2: Desensitized insulin receptors. Glucose unable to enter cells. Endocrine Organs & Hormones Hypothalamus GnRH Þ GHRH Þ TRH Þ CRH Þ Dopamine (PIF) Þ ADH & Oxytocin: "FSH + "LH "GH " TSH "ACTH ¯Prolactin Produced in hypothalamus, released from posterior pituitary Pancreas Insulin Þ Glucagon Þ Somatostatin Þ (GHIH) beta islets, ¯Glucose alpha islets, "Glucose delta islets ¯Insulin, ¯Glucagon Gonads Testosterone in Testes Estrogen / Progesterone in ovaries Anterior Pituitary “FLAT PEG” mnemonic FSH Þ Male: Spermatogenesis Females: Growth of ovarian follicles LH Þ Males: Testosterone Females: Induces ovulation ACTHÞ Synth & release glucocorticoids from adrenal cortex TSH Þ Synth & release triiodothyronine and thyroxine from thyroid ProlactinÞ "Milk Endorphins Þ ¯Pain GH Þ "Growth in bone/muscle "Glucose in bone/muscle Thyroid Gland T4 & T3 Þ made by follicle cells "basal metabolic rate Calcitonin Þ Made by parafollicular (c) cells "Ca2+ in bone ¯Ca2+ in blood ¯Ca2+ absorption in gut "Ca2+ excretion from kidneys Parathyroid Glands Pineal Gland Melatonin controls circadian rhythm PTH Þ ¯Ca2+ in bone "Ca2+ in blood 2+ "Ca absorption in gut ¯Ca2+ excretion in kidneys Bone breakdown releases Ca2+ Activates Vitamin D (Calcitriol) * See appendix for more details on each hormone Posterior Pituitary ADH Þ ¯H2O output in urine vasoconstriction Oxytocin Þ "Uterine contractions "Milk "Bonding behavior POSITIVE FEEDBACK Adrenal Cortex Glucocorticoids: Cortisol / Cortisone "Glucose ¯Protein synthesis ¯Immune system Mineralocorticoids: Aldosterone ¯K+ in blood "Na+ in blood "H2O in blood due to osmosis "blood pressure Androgens: Converted to Testosterone and Estrogen in the gonads. Adrenal Medulla Catecholamines Epinephrine: Anti-histamine "Heart rate "BP Norepinephrine: "Heart rate "BP Biology 6: Respiratory System Pleurae Membranes Air Pathway Nares of nose: Nostrils Trachea: Food / air travels through. Air is warmed / humidified. Vibrissae filter Air ONLY. Epiglottis covering. Contains vocal cords Ciliated epithelium collect debris Bronchi: Ciliated epithelium collect debris Pharynx: Larynx: Bronchioles: The smallest of the branches of the bronchi Alveoli: Sacs where diffusion occurs. Surfactant REDUCES surface tension. Prevents collapse Inhalation Pulmonary Veins, + O2 LUNGS Pulmonary Artery, - O2 Negative pressure breathing Active process Diaphragm & External Intercostal muscles contract Spirometer Measures lung capacity CAN NOT measure TOTAL volume Total Lung Maximum volume of air in the lungs. Capacity: Residual Residual after exhalation (air stays in lungs to Volume: keep alveoli from collapsing). Vital Capacity: Difference between minimum and maximum volume of air in the lungs. Tidal Volume: Volume inhaled and exhaled in a normal breath. Expiratory Volume of additional air that can be forcibly Reserve Volume: exhaled following normal exhalation. Inspiratory Volume of additional air that can be forcibly Reserve Volume: inhaled following normal inhalation. !intrapleural space, !thoracic cavity, ¯pressure !lung volume, ¯lung pressure Air rushes in Exhalation Passive process Muscles relax ¯lung volume, !lung pressure Air leaves lungs Active Exhalation: Internal intercostal & abdominal muscles help force air out Protection from Pathogens Vibrissae: In pharynx Mucous Membranes Mucociliary Escalator Lysozymes: In nasal cavity/saliva. Attack Gram + peptidoglycan Mast Cells: Antibiotics on surface. Inflammation. Allergic reactions Bicarbonate Buffer Medulla Oblongata CO2 (g) + H2O (l) ⇌ H2CO3 (aq) ⇌ H+ (aq) + HCO3- (aq) ! [CO2] Þ Hypercarbia / hypercapria !respiration (exchanging gases) ¯[O2] Þ Hypoxemia !ventilation (air in/out) ¯pH Þ !respiration to blow off CO2 !pH Þ ¯respiration, trapping CO2 Biology 7: Cardiovascular System Deoxygenated Blood Pathway Tricuspid R Atrium Pulmonary R Ventricle Valve Mitral L Atrium Oxygenated Valve Aortic L Ventricle Valve Venules Pulmonary Artery Aorta Venae Cavae AV Node Bundle of His Purkinje Fibers Normal BP: ® Capillaries Arteries: Thick, #muscular, elastic, allows for recoil and helps propel blood forward. Arterioles: Small muscular arteries. Ventricular contraction, AV valves close #" Arterioles Capillaries: 1 cell thick endothelial wall, easy diffusion of gases (O 2 CO2) and waste (NH3, urea). Blood Pressure Ventricular relaxation, SV close, blood atria ® ventricles $%" &" Pulmonary Veins Vasculature “Stab A Big Pickle” acrostic !" All Other Arteries R Atrium (Pacemaker) Diastole All Other Veins Lungs Arteries Electrical Conduction Systole Pulmonary Arteries Valve Veins SA Node Pulmonary Veins Maintained by baroreceptors and chemoreceptors Veins: THIN wall, inelastic. May stretch to accommodate lots of blood, but do not have recoil. Surrounding muscles help pump blood through. Contain valves. Venules: Small veins #BP Þ #ANP (atrial natriuretic peptide) ¯BP Þ #Aldosterone, #ADH (vasopressin) Blood #Osmolarity Þ #ADH Cardiac Output = Heart Rate x Stroke Volume. CO = HR, × SV - Considered a connective tissue. Erythrocytes Formed in bone marrow. No nucleus, mitochondria, or (RBCs) : organelles. Contain Hemoglobin to carry O2. Hematocrit: % of blood composed of RBCs. Blood Type Antigens: Surface proteins on RBCs Rh Factor: Rh+ is dominant. An Rh- person will only create anti-Rh antibodies after exposure to Rh+ blood Blood Type Antigens Produced Antibodies Produced Donate To Receive From A - IA A Anti-B A, AB A, O B - IB B Anti-A B, AB B, O AB - IAIB A and B None AB only A, B, AB, O (universal recipient) O-i none Anti-A and Anti-B A, B, AB, O O only (universal donor) Coagulation When the endothelial lining of a blood vessel is damaged, the collagen and tissue factor underlying the endothelial cells are exposed. Prothrombin ® Thrombin Fibrinogen ® Fibrin Clots are broken down by Plasmin Leukocytes Immune system. Formed in bone marrow. (WBCs): Granulocytes: Neutrophils, eosinophils, and basophils = nonspecific immunity, inflammatory reactions Agranulocytes: Lymphocytes = specific immunity, monocytes digest foreign matter (if monocytes leave bloodstream for organ they are called macrophages) Thrombocytes Cell fragments. Coagulation. (Platelets): Fluid Balance Hydrostatic Pressure: Moves fluid out of the blood vessel and into the interstitial fluid around it. Osmotic Pressure: “Sucking” pressure generated by solutes as they draw H2O into the bloodstream. Oxygen: Carried by hemoglobin. CO2: Some carried by hemoglobin, most exist in the bloodstream as bicarbonate HCO3-. Bicarbonate Buffer CO2 (g) + H2O (l) ⇌ H2CO3 (aq) ⇌ H+ (aq) + HCO3- (aq) ¯pH Þ #respiration to blow off CO2 #pH Þ ¯respiration, trapping CO2 Biology 8: Immune System Structure Innate Immunity: Defenses that are always active but NONSPECIFIC. Skin, mucus, stomach acid, tears etc. Adaptive Immunity: Defenses that take time to activate and are SPECIFIC to the invader. Innate Immune System Non-cellular innate defenses: Skin: Physical barrier. Secretes antimicrobial enzymes like defensins Mucus: On mucous membranes. Traps pathogens. In respiratory system mucous is propelled upward by cilia via mucociliary escalator Lysozymes: In tears and saliva. Antimicrobial compound Complement Can punch holes in the cell walls of bacteria making them System: osmotically unstable, leading to lysis. Also triggers opsonization. Interferons: Given off by virally infected cells. Interfere with viral replication and dispersion Cellular innate defenses: Macrophages: Ingest pathogens and present them on MHC-II. Secrete Cytokines MHC-I: Present in all nucleated cells. Displays endogenous antigen to cytotoxic CD8+ T-cells. MHC-II: Present in professional antigen-presenting cells (macrophages, dendritic cells, some B-cells, and certain activated epithelial cells). Displays exogenous antigen to helper CD4+ T-Cells. Dendritic Antigen-presenting cells in the skin Cells: Natural Killer Attack cells low on MHC, including virally infected cells and Cells: cancer cells Granulocytes: Neutrophils: Activated by bacteria, conduct phagocytosis. Eosinophil: Activated by parasites & allergens !histamines Basophils: Activated by allergens, inhibit blood clotting. Adaptive Immune System Humoral Immunity: Centers on antibody production by B-Cells. Kills antigens while they are floating around in the fluid (humor). B-Lymphocytes Made and mature in bone marrow. Activated in spleen (B-cells): or lymph nodes. Express antibodies on its cell surface. Antibodies (Ig): Produced by plasma cells, which are activated B-Cells. Target an antigen. Contain 2 heavy chains and 2 light chains. Constant region & variable region. Tip of variable region is the antigen-binding region. Hypermutation: Mutation of the antigen binding site on an antibody. Results in varying affinities of antibodies for a specific microbe. 5 diff isotypes (IgM, IgD, IgG, IgE, IgA) Opsonization: Antibodies mark pathogens for destruction. Agglutination: Pathogens clump together into insoluble complexes. Caused by opsonizing pathogens. Memory B-Cells: Lie in wait for a second exposure to pathogen. Secondary response is more rapid and vigorous. Cell-Mediated (Cytotoxic) Immunity: Centers on T-Cells. Responds to cells once they have been infected by the antigen. T-Lymphocytes Made in bone marrow, mature in Thymus. Coordinate (T-cells): immune system and directly kill infected cells. Cellmediated immunity. Positive/Negative Maturation of T-Cells. Facilitated by thymosin. Occurs Selection: in Thymus. Positive Selection: Mature only T-cells that can respond to the presentation of antigen on MHC. Negative Selection: Causes apoptosis in T-cells that are self-reactive Helper T-Cells: Th or CD4+. Respond to antigen on MHC-II. Coordinate rest of the immune system, secreting lymphokines to activate immune defense. Th1 – secrete interferon gamma Th2 – activate B-Cells, in parasitic infections Cytotoxic T-cells: Tc, CTL, or CD8+. “Killer cells”. Respond to antigen on MCH-I and kill virally infected cells Suppressor T-Cells: Treg. Down regulate the immune response after an infection and promote self-tolerance. Defective suppressor T-Cells lead to autoimmune conditions. Memory T-Cells: Serve a similar function to memory B-Cells Autoimmune A self-antigen is recognized as foreign, and the Conditions: immune system attacks normal cells Lymphatic System ¥ ¥ ¥ ¥ ¥ Circulatory system that consists of one-way vessels with intermittent lymph nodes Provides for mounting immune responses Connects to the cardiovascular system via the thoracic duct in the posterior chest Equalizes fluid distribution, transports fats and fat-soluble compounds in chylomicrons Edema results when the lymphatic system is overwhelmed and can’t drain excess fluid from tissues Allergic Reactions: Nonthreatening exposures incite an inflammatory response Immunization: Induces active immunity (activation of B-Cells that produce antibodes) Passive Immunity: Transfer of antibodies to an individual. Breast milk. Biology 9: Digestive System Overview Feeding Behavior Hormones Intracellular Digestion: The oxidation of glucose and fatty acids to make energy. Extracellular Digestion: Process by which nutrients are obtained from food. Occurs in alimentary canal. ADH & Aldosterone: !thirst Glucagon & Ghrelin: !hunger Leptin & Cholecystokinin: !satiety Mechanical Digestion: Physical breakdown of large food molecules into smaller particles. Chemical Digestion: The enzymatic cleavage of chemical bonds such as the peptide bonds of proteins or the glycosidic bonds of starches. Peristalsis: Rhythmic contractions of the gut tube. !parasympathetic nervous system ¯sympathetic nervous system Duodenum First part of small intestine. A basic (pH = 8.5) environment. Site of the majority of chemical digestion. Enzymes in Duodenum Disaccharidases: Brush-border enzymes that break down maltose, isomaltose, lactose, and sucrose into monosaccharides. Aminopeptidase & Brush-border peptidases. Dipeptidase: Digestive Pathway Enteropeptidase: Activates trypsinogen and procarboxypeptidases. Oral Cavity Small Intestine Pharynx Esophagus Large Intestine Stomach Rectum Oral Cavity Mastication starts the mechanical digestion. Salivary amylase and lipase start the chemical digestion of food. Food is formed into a bolus and swallowed. Hormones in Duodenum Secretin: Peptide hormone. Stimulates release of pancreatic juices and slows motility. Cholecystokinin: Stimulates bile release from gallbladder, release of pancreatic juices, and satiety. Absorption and Defecation Pharynx Connects the mouth to the esophagus. The epiglottis prevents food from entering the larynx. Esophagus Propels food to the stomach using peristalsis. Top third has skeletal muscle and is under somatic control. Bottom third has smooth muscle, middle third has combo of both. The middle & bottom are under autonomic control. Stomach An acidic (pH = 2) environment. Four parts: fundus, body, antrum and pylorus. The enzyme pepsin chemically breaks down proteins. The jejunum and ileum of the small intestine are primarily involved in absorption. The small intestine is lined with villi, which are covered with microvilli. Villi: Capillary Bed: Absorbs water-soluble nutrients. Lacteal: Absorbs fat, sends to lymphatic system. Vitamin Absorption: Fat-Soluble: Only A,D,E,K; enter lacteal. Water-Soluble: All others; enter plasma directly. Large Intestine – absorbs H2O and salts, forms feces Cecum: Outpocketing that accepts fluid from small intestine through ileocecal valve. Site of attachment of the appendix. Structure of Colon: Ascending / transverse / descending / sigmoid Gut Bacteria: Produce vitamin K and biotin (vitamin B7 ). Secretory cells that line the stomach Mucous Cells: Produce bicarbonate-rich mucus to protect stomach wall from acid. Chief Cells: Secrete pepsinogen, a protease activated by the acidic environment. Parietal Cells: Secrete HCl and intrinsic factor, which is needed for vitamin B12 absorption. G-Cells: Secrete gastrin, a peptide hormone that !HCl secretion & gastric motility. After processing in the stomach, food particles are now called chyme. Chyme exits through pyloric sphincter ® duodenum. Accessory Organs - Originate from endoderm Pancreas: Acinar Cells produce pancreatic juices that contain bicarbonate, pancreatic amylase, pancreatic peptidases, and pancreatic lipase. Liver: Synthesizes bile, albumin and clotting factors. Process nutrients. Detox: NH3 ® Urea, as well as alcohol & drugs. Liver receives blood from the abdominal portion of digestive tract via Hepatic Portal Vein. Gallbladder: Stores & concentrates bile. CCK stimulates bile release into biliary tree, which merges with pancreatic duct. Biology 10: Kidney and Ski Excretory (urine) Pathway Bowman’s space proximal convoluted tubule ascending limb of the loop of Henle renal pelvis ureter descending limb of the loop of Henle distal convoluted tubule bladder collecting duct urethra Kidney Kidney: Contains a cortex and medulla. Produces urine which dumps into the ureter at the renal pelvis. Urine is then collected in the bladder until it is excreted through the urethra. Nephron: Functioning unit of the kidney. Renal Portal Two capillary beds in series (glomeruli & nephron). Blood System: flow: renal artery ® afferent arterioles ® glomeruli ® efferent arteriole ® vasa recta, which surround nephron ® renal vein. Filtration: Bowman’s capsule moves solutes from blood ® filtrate. Direction and rate determined by hydrostatic and oncotic pressure differentials between the glomerulus and Bowman’s space. Secretion: The movement of solutes from blood ® filtrate anywhere other than Bowman’s capsule. Reabsorption: The mvmt of solutes from filtrate ® blood. pH: Kidney can regulate pH with bicarbonate and H+. Aldosterone: Steroid hormone synthesized in Adrenal Cortex in response to Angiotensin 2 or high [K+]. It is derived from cholesterol. Increases Na+ reabsorption in the distal convoluted tubule and collecting duct, thereby increasing H2O reabsorption. Result: "BP but no change in blood osmolarity ADH Peptide hormone synthesized by hypothalamus and (Vasopressin): released by posterior pituitary. "permeability of the collecting duct to H2O, which "H2O reabsorption. Result: "BP and ¯blood osmolarity, concentrated urine. Nephron Proximal Convoluted Site of bulk reabsorption of glucose, amino acids, Tubule (PCT): soluble vitamins, salt, and H2O. Site of secretion for H+, K+, NH3, and urea Descending Limb of the Permeable to H2O but NOT salt; therefore, as the Loop of Henle: filtrate moves into the more osmotically concentrated renal medulla, water is reabsorbed from the filtrate. Countercurrent The vasa recta and nephron flow in opposite Multiplier System: directions, creating a countercurrent multiplier system that allows maximal reabsorption of water Ascending Limb of the Permeable to salt but NOT to H 2O; therefore, salt Loop of Henle: is reabsorbed both passively and actively. The diluting segment is in the outer medulla; because salt is actively reabsorbed in this site, the filtrate becomes hypotonic compared to the blood Bladder Detrusor Muscle: Muscular lining of bladder. Parasympathetic control Internal Urethral Sphincter: Smooth muscle. Parasympathetic control External Urethral Sphincter: Skeletal muscle. Voluntary control Skin - Epidermis / Dermis / Hypodermis (subcutaneous layer) Epidermis: Stratum Basale: Stem cells ® keratinocytes Stratum Spinosum: Lagerhans cells Stratum Granulosum: Keratinocytes die Stratum Luciderm: Only on thick, hairless skin Stratum Corneum: Mult thin layers, flat keratinocytes Langerhans Cells: Macrophages that are antigen-presenting cells in skin Melanin: Produced by Melanocytes. Protects skin from DNA damage caused by ultraviolet radiation Distal Convoluted Responsive to aldosterone and is a site of salt Tubule (DCT): reabsorption and waste product excretion, like the PCT. Collecting Duct: Responsive to both aldosterone and ADH. Has variable permeability, which allows reabsorption of the right amount of H2O depending on the body’s needs. Dermis: Papillary layer and reticular layer. Sensory: Merkel Cells: Deep pressure & texture Free Nerve Endings: Pain Meissner’s Corpuscles: Light touch Ruffini Endings: Stretch Pacinian Corpuscles: Deep pressure & vibration Hypodermis: Fat and connective tissue. Connects skin to body Thermo- Sweating: Evaporative cooling regulation: Piloerection: Warming Shivering: Warming Vasodilation / Vasoconstriction: Cool / warm Biology 11: Muscular System Skeletal Muscle Sarcomeres ¥ Support & movement, blood propulsion, thermoregulation, striated ¥ Voluntary (somatic) control ¥ Multinucelated Red Fibers: Slow twitch. Support (dark meat). Carry out oxidative phosphorylation. ¥ Basic contractile unit of striated muscle ¥ THICK myosin and THIN actin filaments ¥ Troponin & tropomyosin found on the thin filament and regulate actinmyosin interactions o Z-lines: Define the boundary of each sarcomere o M-line: Middle of sarcomere o I-band: Only actin filaments. o H-zone: Only myosin filaments. o A-band: Contains both actin and myosin. Only part that maintains a constant size during contraction. White Fibers: Fast-twitch. Active (white meat). Anaerobic metabolism. Smooth Muscle ¥ Respiratory, reproductive, cardiovascular, digestive ¥ Involuntary (autonomic) control ¥ Uninucleated ¥ Can display myogenic activity without neural input ¥ Sarcomeres attach end-to-end to become myofibrils. Each myocyte contains many myofibrils Sarcoplasmic Reticulum: Ca2+ filled modified endoplasmic reticulum. Cardiac Muscle ¥ ¥ ¥ ¥ ¥ Sarcolemma: Cell membrane of a myocyte. Contractile tissue of the heart Involuntary (autonomic) control Uninucleated (sometimes binucleated) Can display myogenic activity Cells connected with intercalated discs that contain gap junctions Skeletal System T-tubules: Connected to sarcolemma. Carry signals. - Derived from mesoderm Axial Skeleton: Skull, vertebral column, ribcage, hyoid bone. Appendicular Skeleton: Bones of limbs, pectoral girdle, pelvis. Compact Bone: Strength and density. Spongy Bone: Lattice-like structure of bony spicules known as trabeculae. (cancellous) Cavities filled with bone marrow. Bone Marrow: Red: Filled with hematopoietic stem cells. Yellow: Fat Long Bones: Shafts called diaphysis that flare to form metaphyses and that terminate in epiphyses. Epiphyses contain epiphyseal (growth) plate. Periosteum: Connective tissue that surrounds bone. Ligaments: Attach bones to other bones. Tendons: Attach bones to muscles. Bone Matrix: Osteons are the chief structural unit of compact bone, consisting of concentric bone layers called lamellae, which surround a long hollow passageway, the Haversian canal. Between rings are lacunae, where osteocytes reside, which are connected with cancaliculi. Bone Osteoblasts build bone, osteoclasts resorb bone. Remodeling: Parathyroid Hormone: !resorption of bone ![blood Ca2+]. Vitamin D: !resorption of bone, ![blood Ca2+]. Calcitonin: !bone formation, ¯[Ca2+] in blood. Cartilage: Firm & elastic. Matrix is chondrin. Secreted by chondrocytes. Avascular and is NOT innervated. Joints: Immovable: Fused together to form sutures. Movable: Strengthened by ligaments and contain a synovial capsule. Synovial Fluid: Secreted by synovium, lubricates joints. Fetus: Bones form from cartilage through endochondroal ossification. Skull bones form directly from mesenchyme in intramembranous ossification. Contraction / Relaxation ¥ Begins at neuromuscular junction, where the efferent neuron release acetylcholine that binds to receptors on the sarcolemma, causing depolarization ¥ Depolarization spreads down sarcolemma to T-tubules, triggering the release of Ca2+ ¥ Ca2+ binds to troponin, causing a shift in tropomyosin and exposure of the myosin-binding sites on the actin filament ¥ Shortening of the sarcomere occurs as myosin heads bind to the exposed sites on actin, forming cross bridges and pulling the actin filament along the thick filament. “Sliding filament model” ¥ Muscles relax when acetylcholine is degraded by acetylcholinesterase, terminating the signal and allowing Ca2+ to return to the SR. ¥ ATP binds to myosin head, allowing it to release form actin Simple Twitch: Single muscle fiber responds to brief stimulus. Frequency Summation: Addition of multiple simple twitches before the muscle has a chance to fully relax. Oxygen Debt: Difference between O2 needed and O2 present. Creatine Phosphate: Adds a phosphate group to ADP, forming ATP. Myoglobin: Heme-containing protein that is a muscular oxygen reserve. Biology 12: Genetics and Evolutio Definitions Nucleotide Mutations Alleles: Alternative forms of a gene. Dominant allele only requires 1 copy in order to be expressed. Recessive allele requires two copies in order to be expressed. Point Mutations: The substituting of one nucleotide for another. Frameshift Mutations: Moving the 3 letter reading frame. Genotype: The combination of alleles one has at a given locus. Homozygous: Having two of the same allele. Heterozygous: Having two different alleles. Phenotype: The observable manifestation of a genotype. Dominance: Complete: Only one dominant allele. Codominance: More than one dominant allele. Incomplete: No dominant alleles; heterozygotes have intermediate phenotypes. Penetrance: The proportion of individuals carrying a particular allele that also express an associated phenotype. Expressivity: The varying phenotypic outcomes of a genotype. Genetic Leakage: Flow of genes between species via hybrid offspring. Genetic Drift: When the composition of the gene pool changes as a result of chance. Founder Effect: Bottlenecks that suddenly isolate a small population; inbreeding. Taxonomic Kingdom, phylum, class, order, family, genus, species. Rank: “King Phillip Came Over From Great Spain” Results: Silent: No effect on the protein. Missense: Replace one amino acid with another. Nonsense: A stop codon replaces an amino acid. Insertion/Deletion: Shift in the reading frame, leading to a change in all downstream amino acids. Chromosomal Mutations Much larger mutations, affecting whole segments of DNA. Results: Deletion: A large segment of DNA is lost. Duplication: A segment of DNA is copied multiple times. Inversion: A segment of DNA is reversed. Insertion: A segment of DNA is moved from one chromosome to another. Translocation: A segment of DNA is swapped with a segment of DNA from another chromosome. Analytical Techniques Punnett Squares: Monohybrid cross accounts for 1 gene. Dihybrid crosses account for two genes. Sex-linked cross is linked to the X chromosome. Recombination The likelihood of two alleles being separated during Frequency: crossing over in meiosis. Farther = !likely Mendel’s Laws Law of Segregation: An organism has two alleles for each gene, which segregate during Anaphase I. Because of this, gametes carry only one allele for a trait. Hardy-Weinberg If a population meets certain criteria (aimed at a lack Principle: of evolution), then the allele frequencies will remain constant. Law of Independent The inheritance of one allele does not influence the Assortment: probability of inheriting a given allele for a different trait (except for linked genes). Hardy-Weinberg P + q = 1 Equation: P2 + 2Pq + q2 = 1 P = dominant-allele-freq q = recessive-allele-freq Evolution Experiments Natural Selection: The mechanism for evolution is natural selection. Experiments to support DNA as genetic material. Griffith: Demonstrated transformation. Heat-killed smooth (virulent) strain of bacteria still transformed rough strain into smooth. Avery-MacLeod- Degradation of DNA led to a cessation of bacterial McCarty: transformation. Degradation of proteins did not. Hershey-Chase: Confirmed DNA is the genetic material because only radiolabeled DNA could be found in bacteriophageinfected bacteria. Modern Synthesis Neo-Darwinism. Mutation and recombination are Model: mechanisms of variation. Differential reproduction. Inclusive Fitness: If a population meets certain criteria (aimed at a lack of evolution), then the allele frequencies will remain constant. Punctuated Considers evolution to be a very slow process with Equilibrium: intermittent rapid bursts of evolutionary activity. Mode of Natural Stabilizing Selection: Keeps phenotypes in a narrow Selection: range, excluding extremes. Directional Selection: Moves the average phenotype toward an extreme. Disruptive Selection: Moves toward two different phenotypes at the extremes, can lead to speciation. Adaptive Radiation: Rapid emergence of multiple species from a common ancestor, each has a niche. Isolation: Reproductively isolated from each other by pre- or postzygotic mechanisms. Divergent Evolution Parallel Evolution Convergent Evolution Molecular Clock The degree of difference in the genome between Model: two species is related to the amount of time since the two species broke off from a common ancestor.