NUTR 3210 Lecture 12: NUTR3210 - Lect 12

• School: University of Guelph
• Department: Nutrition
• Course: NUTR 3210
• Professor: David Mutch

Document Summary

Protein digestion: mouth, no enzymatic digestion, mechanical forces, stomach, hcl in gastric juice, pepsin (endopeptidase, pancreas, produces pancreatic juice that contains zymogens, small intestine, complete breakdown of foods. Protein digestion in the stomach: hcl secreted from parietal cells; triggered by gastrin, acetylcholine, histamine, etc, hcl has two functions, 1. Activate pepsin: pepsin begins to break-down polypeptide chain, released in stomach as pepsinogen (inactive zymogen, endopeptidase (breaks peptide bonds in polypeptide, active at an acidic ph, creates large polypeptides, oligopeptides, and free aas. Enterokinase is used to activate trypsinogen to trypsin, so that it will activate the other digestive enzymes. Increase synthesis of heat shock proteins (chaperones: produce mucus, which presents bacterial translocation. Amino acid absorption: liver, effective clearance (50-65%, ~20% used for synthesis, ~80% metabolized (cid:862)fi(cid:396)st pass (cid:373)eta(cid:271)olis(cid:373)(cid:863, not bcaa (anabolic signals for extrahepatic tissues like muscle) P(cid:396)otei(cid:374) (cid:862)qualit(cid:455)(cid:863: 4 components to consider, aa co(cid:373)positio(cid:374): a(cid:374)(cid:455) p(cid:396)otei(cid:374) that p(cid:396)o(cid:448)ides esse(cid:374)tial aa is (cid:272)o(cid:374)side(cid:396)ed (cid:862)high (cid:395)ualit(cid:455)(cid:863), a(cid:374)i(cid:373)al > pla(cid:374)t (e(cid:454).