LIFE SCIENCE

Detailed explanation-1: -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: -Abstract. Pepsin is an aspartic protease that acts in food digestion in the mammal stomach. An optimal pH of around 2 allows pepsin to operate in its natural acidic environment, while at neutral pH the protein is denatured.

Detailed explanation-3: -Pepsin works in the highly acidic conditions of the stomach. It has an optimum pH of about 1.5. On the other hand, trypsin works in the small intestine, parts of which have a pH of around 7.5.

Detailed explanation-4: -Pepsin, the first animal enzyme discovered (Florkin, 1957), is an acidic protease that catalyzes the breakdown of proteins into peptides in the stomach, while it does not digest the body’s own proteins.

Detailed explanation-5: -This observation is as expected since the optimal pH for pepsin’s proteolytic activity is 1.6, and is consistent with the observation that pepsin optimally degrades dietary proteins between a pH range of 1.2 to 2.5 [26, 27].