2-1g_breakdown_of_aminoacids

2-1g_breakdown_of_am - Catabolism of amino acids and excretion of nitrogen Dietary protein is enzymatically degraded to amino acids In the stomach

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Catabolism of amino acids and excretion of nitrogen
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In the stomach, parietal cells of the gastric glands secrete HCl and chief cells of the gastric glands secrete pepsinogen. At low pH (1.5-2.5) most proteins are denatured. Pepsinogen is a zymogen that cleaves a 42 amino acid peptide from itself to become active pepsin . Pepsin cleaves at the N-terminal side of Y, F, and W. As the acidic stomach contents enter the small intestine, the low pH stimulates the secretion of secretin into the blood, stimulating the pancreas to secrete bicarbonate , raising the pH to ~7. The presence of amino acids in the duodenum causes secretion of cholecystokinin , which stimulates secretion of pancreatic enzymes, including trypsinogen , chymotripsinogen , and procarboxypeptidase . The cells of the small intestin secrete enteropeptidase , which activates trypsinogen to trypsin . Trypsin then activates the other proteases and itself. Trypsin cleaves at R and K, chymotrypsin at F, Y, and W. The cells of the small intestine also secrete amino peptidase . The amino acids released by the proteases are adsorbed by the epithelial cells of the small intestine, passed into the blood, and transported to the liver. Celiac disease
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This note was uploaded on 02/17/2012 for the course CHEM 212 taught by Professor Staff during the Fall '10 term at Rutgers.

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2-1g_breakdown_of_am - Catabolism of amino acids and excretion of nitrogen Dietary protein is enzymatically degraded to amino acids In the stomach

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