Which statement describes the conversion of pepsinogen to pepsin?

Which statement describes the conversion of pepsinogen to pepsin?

• A. Hydrochloric acid converts pepsinogen to pepsin
• B. Bile acids convert pepsinogen to pepsin
• C. Pancreatic enzymes convert pepsinogen to pepsin
• D. Pepsin converts pepsinogen to pepsin

Answer: (B)

Activation of pepsinogen to pepsin occurs in the stomach when it meets the highly acidic environment created by hydrochloric acid. The stomach’s acid cleaves a short amino-terminal segment from pepsinogen, exposing the active site and forming pepsin. This activation can be amplified by autocatalysis, as the initially formed pepsin helps convert more pepsinogen. Bile acids do not participate in this step; they function in fat digestion in the small intestine. Pancreatic enzymes activate zymogens in the intestine, not pepsinogen. So the essential trigger is acid in the stomach, not bile acids or pancreatic enzymes.

Activation of pepsinogen to pepsin occurs in the stomach when it meets the highly acidic environment created by hydrochloric acid. The stomach’s acid cleaves a short amino-terminal segment from pepsinogen, exposing the active site and forming pepsin. This activation can be amplified by autocatalysis, as the initially formed pepsin helps convert more pepsinogen. Bile acids do not participate in this step; they function in fat digestion in the small intestine. Pancreatic enzymes activate zymogens in the intestine, not pepsinogen. So the essential trigger is acid in the stomach, not bile acids or pancreatic enzymes.