Protein Digestion 111309

Protein Digestion 111309 - PROTEINS & PEPTIDES We consume...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 P ROTEIN D IGESTION & A BSORPTION ( PG . 189-194) Lia M. Nightingale, Ph.D. We consume ~100 grams of exogenous protein per day from: Animal products (meat, dairy, etc.) Plant proteins (legumes, nuts, etc.) We get ~200 grams of endogenous protein from: Digestive enzymes Sloughed cells Digested by efficient proteases Lys Lys Lys Gly Gly Val His Met Phe Only ~10 grams lost/day in feces. PROTEIN DIGESTION- MOUTH No protein digestion occurs in the mouth PROTEIN DIGESTION- STOMACH HCl is released from parietal cells in response to gastrin 1. structure of protein 2. Converts pepsinogen (inactive) to pepsin (active) HCl or Pepsin Removes 46 amino acids to activate Pepsinogen Pepsin PROTEIN DIGESTION- STOMACH Pepsin is an endopeptidase Lys Tyr Lys Trp Val Met His Trp Phe Results in large polypeptides, oligopeptides, & free amino acids. Digests internal peptide bonds PROTEIN DIGESTION- SI Chymerelease into SI stimulates release of secretin & CCK (cholecystokinin) Secretin & CCK stimulate release of bicarbonate , water, from pancreas Neutralizes stomach acid Inactive enzymes
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 PANCREATIC ZYMOGENS Enterokinase * or Trypsin Trypsinogen Trypsin Trypsin Chymotrypsinogen Chymotrypsin Trypsin Procarboxypeptidase Carboxypeptidase Trypsin Proelastase Elastase *A brushborder enzyme in SI PANCREATIC ENZYMES - ENDOPEPTIDASES Trypsin Chymotrypsin Elastase Collagenase Digests internal peptide bonds Digests protein in collagen Digests protein in elastin Products of pancreatic endopeptidase digestion: peptides and amino acids PANCREATIC ENZYMES - EXOPEPTIDASES Digests external peptide bonds Digests protein from the carboxy terminal Carboxypeptidase C R 2 H C O N H C R 3 H C O O - N H Amino end
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/07/2012 for the course PHCH 51311 taught by Professor Nightingale during the Summer '11 term at Palmer Chiropractic.

Page1 / 7

Protein Digestion 111309 - PROTEINS & PEPTIDES We consume...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online