ANSI 3543 Lecture Notes - Lecture 10: Gastrointestinal Tract, Mastication, Lactase
Document Summary
All living organisms require some form of food or nourishment. Digestion: breakdown of large molecules to simpler smaller chemical compounds that can be absorbed. Complete when molecules are small enough to be absorbed. Physical or mechanical action: grinding in gi tract, omassum - ruminant, digestive turbulence, chewing mastication, hydrochloric acid stomach protein, bile acids produced by liver. Enzymatic action 1 importance: proteins all enzymes are proteins. Lipid digestion and absorption: specific substrates (lactase for lactose, narrow ph (2,7-7. 5) stomach, si, cofactors are needed (mineral and vitamins) Mg, zn, etc: function by hydrolysis. Absorption: set of processes that result in passage of small molecules from lumen of gut through cells of. Intestinal modifications to increase surface area aka microvilli. Passive diffusion: passage of substance from lumen into intestinal cell due to concentration gradient, high concentration to low concentration, no energy required.
