Chapter 41

materials that n animal's cells require but cannot syntehsize; therefore they're obtained from diet; ex: essential amino acids, essential fatty acids, vitamins, and minerals

8 of the 20 amino acids derived from food in a prefabricated form required to make proteins that CAN'T be synthesized; other 12 can be created if diet includes organic nitrogen; all are present in animal proteins (complete) but are lacking in plant proteins (incomplete)

fatty acids that are unsaturated and can't be made; deficiencies in this class of nutrients are rare cause seeds grains and vegetables furnish ample qualities of fatty acids

organic molecules you need in small amounts (13 in total); 1) fat-soluble: K, A, D, E 2) water-soluble: B complex & vitamin C (required to produce connective tissue)

more easily destroyed by heat; hard to overdose; easily wash out in urine

greater risk of overdose; hang around in body more b/c they stay in bodily tissues

inorganic substances that can't be made from organic molecules; ingesting large amounts can sometimes cause toxic side effects/upset homeostatic balance

most animals (+ humans) that eat large pieces of food (use adaptations such as tongues, claws, pincers, teeth, tentacles, trunks, limbs)

animals that suck nutrient-rich fluid from a living host; ex. mosquito, bees, hummingbird

aquatic animals that sift small food particles form the water; ex. whales, clams, oysters

a tube/complete digestive tract that goes between an animals two openings (mouth and anus)

alternating waves of contraction and relaxation in the smooth muscles lining the alimentary canal

an enzyme in saliva produced by salivary glands in the mouth hydrolyzes starch & glycogen, so breaks down polysaccharides into smaller versions called maltose

a protease (or protein digesting enzyme) that breaks proteins into small polypeptides; 1st released as pepsinogen (inactive form) by chief cells; turned into pepsin by HCl and subsequently pepsin itselfn (ex. of positive feedback)

found in the lumen of the small intestine but MADE/SECRETED by the pancreas: proteases secreted in inactive forms

made in the liver, stored in the gallbladder, and responsible for digestion of lipids in the small intestine [pancreatic lipase also digests fat in lumen of s. intestine]

hormone produced by pancreas; stimulated by rising blood gluocose levels after eating; causes liver and muscle cells to store glucose as glycogen --- as a result blood glucose levels DROP

hormone also produced by pancreas; stimulated by blood glucose levels dropping BEYOND set point; promotes the breakdown of glycogen in the liver and the release of glucose into the blood, increasing levels of blood glucose