ANATOMY

Detailed explanation-1: -Hydrochloric acid (HCl), another component of the gastric juice, plays a crucial role in creating the pH required for pepsin activity. Parietal cells produce HCl by secreting hydrogen and chloride ions. When pepsinogen and hydrochloric acid exist together in the gastric juice, pepsin takes its active form.

Detailed explanation-2: -Pepsin is most active in acidic environments between pH 1.5 to 2.5. Accordingly, its primary site of synthesis and activity is in the stomach (pH 1.5 to 2).

Detailed explanation-3: -Pepsin works in the highly acidic conditions of the stomach. It has an optimum pH of about 1.5.

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.