Question

Which acid renders the acidic pH in stomach for the activity of protein digesting enzymes ?

• A. HCL
• B. \(H_2SO_4\)
• C. \(HNO_3\)
• D. \(HCO_3\)

Answer 1

The Correct Option is A

To solve the problem, we need to identify which acid creates the acidic environment in the stomach that is necessary for protein-digesting enzymes to function.

1. Protein-Digesting Enzymes in the Stomach:
The primary enzyme responsible for digesting proteins in the stomach is pepsin. Pepsin is secreted in an inactive form called pepsinogen, which becomes active in the presence of an acidic pH.

2. Source of Acidity:
The acidic pH in the stomach is provided by hydrochloric acid (HCl), which is secreted by the parietal cells in the lining of the stomach.

3. Role of HCl:
- Activates pepsinogen to pepsin
- Provides the optimum acidic pH for enzyme activity
- Helps in killing harmful microbes ingested with food

4. Eliminate Other Options:
- \( \text{H}_2\text{SO}_4 \) (Sulfuric acid) – not found in the body
- \( \text{HNO}_3 \) (Nitric acid) – not secreted in the stomach
- \( \text{HCO}_3^- \) (Bicarbonate) – a base, used to neutralize acid

Final Answer:
The acid that renders the acidic pH in the stomach is HCl (Hydrochloric acid).