Question

The pH of the food is brought at .......... by HCl produced in a man's stomach.

• A. 0.5
• B. 2
• C. 1.5
• D. 3

Answer 1

The correct option is C 1.5

The pH of gastric acid is 1.5 to 3.5 in the human stomach lumen, the acidity being maintained by the proton pump $H^{+}$ / $K^{+}$ ATPase. The resulting highly acidic environment in the stomach lumen causes proteins from food to lose their characteristic folded structure (or denature). This exposes the protein's peptide bonds. The gastric chief cells of the stomach secrete enzymes for protein breakdown (inactive pepsinogen and rennin).