CHAPTER 44 Animal Nutrition PPT Notes 4 27 2014 o o o o o o o o o o o o o o the classification animal has 2 basic requirements chemical energy from ATP burning 3 energy yielding nutrients fat lipids carbohydrates protein carbon containing molecules heterotrophs organisms that obtain energy nutrients they need from other organisms rather than making their own food 4 processes needed to obtain energy from food ingestion act of bringing food into digestive tract digestion the physical chemical breakdown of food into molecules that can absorbed into the body of an animal occurs in digestive tract alimentary canal gastrointestinal GI tract begins mouth ends anus incomplete digestive tract single opening doubles as place where food enters wastes exit gastrovacular cavity is site of digestion absorption hydra example complete digestive tract 2 openings start mouth ends anus interior of tube communicates directly w external environment via openings 3 advantages in comparison to incomplete tract animals can eat large pieces of food chemical physical processes can be separated within the canal so they occur independently of each other in a prescribed sequences material can be ingested digested continuously food flow in one direction absorption the uptake of ions small molecules nutrients derived from food across the lining of the intestine into the bloodstream elimination removal of waste from the body o o o essential amino acids the 8 out of the 20 amino acids that cannot be synthesized by humans essential in diet essential fatty acids the 2 fatty acids that cannot be synthesized by humans essential in diet vitamins organic compounds vital for health only needed in minute amounts function as coenzymes in critical rxns o 13 essential vitamins 9 water soluble 8B vitamins vitamin C 4 fat soluble vitamins A D E K electrolytes inorganic ions that influence osmotic balance are required for normal membrane function minerals inorganic substances that fulfill functions not performed by electrolytes important components of cofactors or structural materials 3 key hormones regulate digestion gastrin found in stomach stimulates secretion of HCl by parietal cells secretin secreted by cells of small intestine when food arrives induces flow of bicarbonate ions from pancreas neutralizes stomach acids cholecystokinin stimulates secretion from liver gall bladder pancreas into small intestine aids in digestion of macronutrients stomach protein digestion begins in the stomach gastric juice contains HCl works with enzyme pepsin to begin protein digestion HCl denatures breaks down secondary and tertiary structures of proteins pepsin breaks down peptide bonds btwn amino acids of proteins chief cells specialized stomach cells that contain pepsin precursor pepsinogen that is converted to pepsin in presence of HCl secretion of protein digesting enzyme in inactive form prevents destruction of proteins in cells where enzyme is synthesized secretory cells in stomach lining secretion of HCl by parietal cells ruminants have a 4 chambered stomach specialized for digesting cellulose rather than protein ferment glucose breakdown from cellulose ex cows rumen largest chamber of ruminant stomach rumen reticulum omasum abomasum 4 27 2014 able to harvest energy from cellulose due to combination of specialized anatomical structures and symbiotic relationships w bacteria unicellular protists cellulase breaks down beta 1 4 glycosidic links in cellulose glucose anaerobically processed fatty acids yielded fatty acids become main energy source o o o o o o o o o o pancreas produces enzymes for digestion of other macromolecules enzymes secreted to small intestine enzymes from the pancreas called protesases digest polypeptides to monomers digest protein many kinds of proteases specific to different kinds of polypeptides synthesized in inactive form by pancreas transferred through pancreatic duct to small intestine activated enterokinase activates pancreatic enzymes nucleases digest RNA and DNA pancreatic amylase continues digestion of carbohydrates that started in mouth pancreatic lipase digests lipids gallbladder stores bile bile salts emulsifying agents that break up large fat globules so lipase can digest them synthesized in liver secreted in bile bile pH in small intestine emulsifies fat into small globules pancreatic lipase breaks bonds in complex fasts release fatty acids small lipids large intestine colon conducts water and vitamin K absorption solutes from digested material brought into epithelium of small intestine by active transport water does osmosis o o water absorbed to form feces held in rectum until eliminated by defecation o water absorbed in large intestine through aquaporins o o bacT residing in colon produce vitamin K which helps w blood clotting cecum outpocketing of digestive tract beginning of large intestine fermentation chamber for processing cellulose enlarged in herbivorous species reduced in humans to form appendix vestigial organ storing immune cells bacT small intestine site where protein digestion ends major site of digestion absorption nutritional homeostasis glucose as a case study too much or too little nutrient fatal removal of a pancreas from a dog resulted in high glucose levels pancreas secretes compound needed for removing glucose from blood digestive enzymes in pancreas destroying active agent during extraction process diabetes mellitus abnormally high levels of glucose in blood caused by problems w insulin hormone insulin hormone secreted by pancreas when blood glucose levels are high o o binds to receptors through body cells increase rate of glucose uptake processing decreases blood glucose levels develops in people who don t synthesize insulin type I diabetes mellitus type II diabetes mellitus type 1 treated w injections type 2 treated w prescribed diets monitoring blood glucose levels drugs that increase cellular responsiveness to insulin epidemic of type 2 diabetes poor lifestyle conditions the culprit correlation w obesity o BMI used to determine obesity 4 27 2014 4 27 2014 4 27 2014 CHAPTER 44 Animal Nutrition Blue Thread Questions 4 27 2014 If you understand the importance of surface are in the small intestine you should be able to explain why surface area is so much higher in this structure than it is in the stomach or esophagus Why did the researchers inject the RNAs into frog eggs into frog eggs instead of into rabbit epithelial cells If you understand this concept you should be to
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