Curdling of milk in the stomach is due to the action of -

Options

A. Pepsin
B. Rennin
C. Ptyalin
D. Enterokinase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which enzyme is responsible for the curdling of milk in the stomach.

2. **Identifying the Conditions for Curdling**: Curdling of milk occurs when the pH level of the milk decreases, creating an acidic environment. This acidic medium is crucial for the curdling process.

3. **Role of Enzymes**: In the stomach, various enzymes are involved in digestion. The key enzymes mentioned are pepsin, renin, talan, and enterokinase.

4. **Analyzing Each Enzyme**:
- **Pepsin**: This enzyme primarily breaks down proteins into polypeptides but is not specifically responsible for curdling milk.
- **Renin**: This enzyme is specifically responsible for curdling milk, especially in infants. It acts on casein, the main protein in milk, facilitating its digestion.
- **Talan**: This enzyme is not commonly recognized in the context of milk digestion.
- **Enterokinase**: This enzyme activates trypsinogen to trypsin but does not play a role in curdling milk.

5. **Conclusion**: The enzyme responsible for the curdling of milk in the stomach is **renin**.

**Final Answer**: The curdling of milk in the stomach is due to the action of **renin**.

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