Read the following reactions and choose the correct option
(i) `"Pepsinogen"overset(HCl)rarr " Pepsin " `
(ii) `"Proteins" overset("pepsinogen")rarr "Proteoses + Peptones "`
(III)`"Trypsinogen "overset(HCl)rarr " Trypsin " `
(Iv) `" Chymotrypsinogen" overset("enterokinase")rarr"Chymotrypsin "`
(v ) `"Peptones"overset("trypsin")rarr "Dipeptides"`

Options

A. I alone is correct
B. I and v alone are correct
C. iii and v alone are correct
D. ii alone is are correct

Answer

To solve the question regarding the reactions involving digestive enzymes, we will analyze each reaction step by step.

### Step-by-Step Solution:

1. **Analyzing Reaction (i)**:
- The reaction states: "Pepsinogen" overset(HCl) rarr "Pepsin".
- **Explanation**: Pepsinogen is an inactive enzyme (zymogen) that is converted to its active form, pepsin, in the presence of hydrochloric acid (HCl) in the stomach.
- **Conclusion**: This reaction is **correct**.

2. **Analyzing Reaction (ii)**:
- The reaction states: "Proteins" overset("pepsinogen") rarr "Proteoses + Peptones".
- **Explanation**: The correct enzyme that breaks down proteins into proteoses and peptones is pepsin, not pepsinogen. Pepsinogen is the inactive form, and it does not directly act on proteins.
- **Conclusion**: This reaction is **incorrect**.

3. **Analyzing Reaction (iii)**:
- The reaction states: "Trypsinogen" overset(HCl) rarr "Trypsin".
- **Explanation**: Trypsinogen is also an inactive enzyme that is converted to trypsin, but this conversion occurs in the intestine with the help of enterokinase, not HCl.
- **Conclusion**: This reaction is **incorrect**.

4. **Analyzing Reaction (iv)**:
- The reaction states: "Chymotrypsinogen" overset("enterokinase") rarr "Chymotrypsin".
- **Explanation**: Chymotrypsinogen is converted to chymotrypsin, but this conversion is actually facilitated by trypsin, not enterokinase.
- **Conclusion**: This reaction is **incorrect**.

5. **Analyzing Reaction (v)**:
- The reaction states: "Peptones" overset("trypsin") rarr "Dipeptides".
- **Explanation**: Trypsin acts on peptones to break them down into smaller peptides, including dipeptides.
- **Conclusion**: This reaction is **correct**.

### Final Conclusion:
From the analysis:
- Reaction (i) is correct.
- Reaction (ii) is incorrect.
- Reaction (iii) is incorrect.
- Reaction (iv) is incorrect.
- Reaction (v) is correct.

Thus, the correct options are **1st and 5th reactions**.