Amino Acids, Proteins and Porphyrins
The enzyme primarily responsible for protein degradation in stomach is:
a. Protein Digestion begins in the stomach
b. Gastric juice →is a clear, pale yellow of 0.2 to 0.5% HC1 with pH of about 1., 97-99% water.
The remainder of gastric juice contain-
i. Mucin and Inorganic salt
ii. Digestive enzymes: -
A. Pepsin — secreted by chief cells, as zymogen (pepsinogen, inactive)
a. Pepsin is an Endopeptidase, is specific for peptide bonds by Aromatic amino acids (eg. Tyrosine) or dicarboxylic amino acids (eg. glutamate.
b. Pepsin is the major digestive function of the stomach
B. Rennin (chymosin, Rennet) →coagulate milk, found in Infants but absent in Adult. In the
presence of ca++, rennin changes casein of milk irreversibly to a paracasein, which then acted
C. Lipases →continues the digestion of Triacylglycerol.
Pancreatic secretion contains: -
a. Trypsin, chymotrypsin and Elastase→ are endopeptidases
e. Bile salt
i. cholesteryl ester hydrolase
j. phospholipase A