BIOD 121 Portage module 2 Latest Version Graded A

BIOD 121 Portage module 2 Latest Version Graded A protein digestion 1. cooking 2. pepsin (in stomach) 3. cholecystokinin -CCK (small intestine) - travels to pancreas, releases trypsin back to SI 4. trypsin - breaks peptide chains 5. amino acids absorbed through portal vein to liver digestion transforming food into basic nutrients that can be absorbed and used by the body sensory stimuli before digestion cognition sound odor appearance taste peristalsis Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system. digestive enzymes catalyze the chemical reactions required to break down food particles into smaller parts, which prepares the nutrients for absorption mucosa intestinal wall, innermost layer circular and longitudinal muscles mix and move food along the GI tract passive diffusion substances move without energy high to low concentration facilitated diffusion special protein carrier is required to help substances cross in or out of the cell high to low concentration active transport requires energy low to high concentration GI tract 6 main parts 1 - mouth 2 - esophagus 3 - stomach 4 - small intestine 5 - large intestine 6 - rectum GI tract accessory organs salivary glands, liver, gallbladder, pancreas mouth alter food particles for swallowing mechanical and chemical digestion saliva mucus plus digestive enzymes mucus lubricates food particles for swallowing salivary amylase Enzyme in saliva that breaks down starch lingual lipase a fat-splitting enzyme secreted by cells at the base of the tongue esophagus transports food to the stomach epiglottis a flap of cartilage that covers the trachea while swallowing sphincter muscle circular muscle at the