Zoology 101: Animal Biology Last Lecture Outline Lecture 20 1. Females and the X chromosome2. Energy Processing 3. Electron transport/Chemiosmosis Current Lecture Outline1. Finish up of last lecture and Fermentation2. Energy and exchange Finish up of last lecture and Fermentation • Each e- donates ETC by NADH → 2.5 ATP's, FAD(H)2 → 1.5 ATPs • 10 NADH X 2.5 ATPs = 25 ATPs per glucose by oxidative • 2 FAD(H)2 X 1.5 ATPs = 3 ATPs per glucose by oxidative • 32 ATPs total (Last lecture was an estimate based on a movie) • NADH contributes more than FAD(H)2 because NADH contributes electrons at a different point of the ETC• If oxygen is present, ATP is made aerobically; if oxygen isn't present, ATP is made via substrate-level phosphorylation, only a small amount of ATP is made → Fermentation • Lactic acid fermentation: glycolysis occurs when no oxygen is present, only occurs for a short amount of type, pyruvate doesn't go through the Kreb's cycle. Becomes waste product → lactic acid• Ethanol fermentation → glycolysis occurs when no oxygen is present, only occurs for a short amount of type, pyruvate doesn't go through the Kreb's cycle. Waste product → ethanol (beer, wine)• All food molecules get hydrolyzed • Monomers/smaller units at various points in the pathway• e- all get picked up by shuttles and go to the ETC Energy and exchange • Animals exchange materials with the environment: Digestion, respiration, circulation • Exchange occurs as substances are dissolved in an aqueous solution move across plasma membrane of each cell • Amoeba → single-celled organism, entire surface area is in contact with environment• Multicellular organisms → exchange must occur across each cell, every cell must have access to environment • Simple animals : can have direct exchange with environment, thin, flat shape, few cell layers, live in moist environments (Hydra, flatworm)• Complex animals: specialized exchange surfaces, external or internal, Large surface area (folds and branches), connected to a circulatory system, thin layer of epithelial cells/sheets covering internal/external cavities, moist (interstitial fluid)• Food must be ingested (Act of eating food; bulk feeders eat relatively large pieces of food)◦ Digested- food broken down into pieces small enough to absorb◦ Absorbed- cells take up food molecules ( → circulation) ◦ Elimination- undigested food released from body• Chemical digestion- chemical breakdown of food by hydrolytic enzymes • Mechanical digestion- physical breakdown of food molecules, increases surface area for hydrolytic enzyme action • Mouth (oral cavity): mechanical digestion- type of teeth indicates the type of food eaten◦ Chemical digestion: saliva▪ salivary amylase: starches (carbs)▪ Lingual lipase: fat▪ Mucus: lubricates food (bolus)▪ Antibacterial agents: first line of defense to bacteria◦ Peristalsis: wave of muscular movement to move food through digestive system • Stomach: Storage, some stomachs are highly adapted for storage ◦ Mechanical: peristalsis/churning ◦ Chemical: gastric juice → digests meat/protein ▪ H-Cl: pH 2, kills bacteria, denatures protein, activates protease ▪ pepsin → protease ◦ Components of gastric juices inactive until released into lumen of stomach◦ Gastric pit: lined with epithelial celss ▪ mucus cell produced mucus, protecting stomach ▪ parietal- secretes H+ and Cl-, combine to make H-Cl to go out into major part of stomach ▪ Chief- inactive pepsin- “pepsinogen”, needs a switch to turn it on → acid• Positive feedback: amplifying a physiological change; once food is gone, response goes down • Cells in stomach aren't damaged by pepsine and H-Cl because gastric juice isn't released until food arrives in stomach, mucus cell secretes protective mucus, rapid mitosis (every 3 days) • Ulcer: damage to lining of stomach◦ heliobactor pylori correlates with ulcers • Acid chyme leaves stomach and goes to small intestine • Bicarbonate from pancreas neutralizes acid
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