HCl present in gastric juice changes

Options

A. Pepsinogen to pepsin
B. Pro-rennin to rennin
C. Disaccharides to monosaccharides
D. Both (A) and (B)

Explanation

### Step-by-Step Solution:

1. **Understanding Gastric Juice Composition**: Gastric juice is a digestive fluid produced in the stomach, primarily composed of hydrochloric acid (HCl), pepsinogen, intrinsic factor, and mucus.

2. **Role of HCl**: The hydrochloric acid in gastric juice lowers the pH of the stomach to about 1.8, creating an acidic environment that is essential for digestion.

3. **Activation of Pepsinogen**: One of the main roles of HCl is to convert the inactive enzyme pepsinogen into its active form, pepsin. Pepsin is crucial for the digestion of proteins, breaking them down into smaller peptides.

4. **Function in Infants**: In infants, HCl also activates prorenin, converting it into renin. Renin is important for digesting milk proteins, which is particularly relevant for infants who consume milk as their primary source of nutrition.

5. **Conclusion**: Therefore, the presence of HCl in gastric juice changes pepsinogen to pepsin and prorenin to renin, facilitating protein digestion in both adults and infants.

### Final Answer:
HCl present in gastric juice changes pepsinogen to pepsin and prorenin to renin.

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