GENERAL HISTOLOGY

Detailed explanation-1: -Pepsin is a stomach enzyme that serves to digest proteins found in ingested food. Gastric chief cells secrete pepsin as an inactive zymogen called pepsinogen. Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin.

Detailed explanation-2: -Pepsin cleaves peptide bonds in the amino-terminal side of the cyclic amino acid residues (tyrosine, phenylalanine, and tryptophan), breaking the polypeptide chains into smaller peptides (Fange and Grove, 1979).

Detailed explanation-3: -Protease (made in the pancreas; breaks down proteins)

Detailed explanation-4: -The stomach releases gastric juices containing hydrochloric acid and pepsin (an enzyme) which initiate the chemical breakdown of protein. Hydrochloric acid (HCl) in the stomach begins protein digestion by denaturing the protein; denaturation results in the loss of the protein’s function.

Detailed explanation-5: -Pepsinogen (42.5 kDa) is a proenzyme, or zymogen, activated by H+ ions in gastric secretions. Its activity is further potentiated by its active form, pepsin. This mechanism, by which an enzyme activates its own zymogen, is called autocatalysis.