BIO 012 Lecture Notes - Lecture 18: Chylomicron, Duodenum, Autocatalysis
Document Summary
Stomach has golds (is highly convoluted) to increase surface area. Gastric pits are in these convulsions as the deep folds. 1. chief cells- cells that release proteolytic enzymes like pepsin (orignally pepsinogen in its zymogen state) Mostly releases zymogens: parietal cells- releases hydrogen ions into the stomach to increase the acidity of the stomach acid. To help digest food: mucosa- secreted to protect the stomach lining from the stomach acid. Digestion of a protein zymogen: inactive enzyme pepsinogen: inactive protein enzyme. The introduction of hydrogen ions (acid) cleaves an amino acid off a pepsinogen that had been masking its active site, turning it into a active pepsin enzyme. Autocatalysis- a process by which one activated pepsin can go on to activate other inactive pepsinogens; positive feedback chymotrypsin: cleaves proteins into amino acid chains. A chain of amino acids has two ends: an amino end and a carboxyl end endopeptidase- cleaves an amino acid down its center.
