Question

Gastric enzyme pepsin acts only in acidic medium with in a limited pH concentration. The pH range is

• A. 1.2 to 1.8
• B. 1 to 1.5
• C. 2 to 3.5
• D. 1.5 to 2.5

Answer 1

Answer: (D)

1.5 to 2.5

Pepsin is a strongest endopeptidase enzyme of the alimentary canal, which is present as inactive zymogen form in gastric juice. The gastric juice contains hydrochloric acid, which helps maintain the pH in the range of 1.5 to 2.5 (very acidic), for optimum activity of pepsin. The main function of hydrochloric acid is to convert inactive enzymes (zymogens) into active enzymes. Pepsin breaks proteins into smaller molecules, peptones, proteoses and peptides.

So, the correct answer is option D.