Which of the following is not a proteolytic enzyme
or
Which of the following belongs to the class of pepsin and trypsin

Options

A. Pepsin
B. Trypsin
C. Erepsin
D. Renin

Explanation

**Step-by-Step Solution:**

1. **Understanding Proteolytic Enzymes**: Proteolytic enzymes, also known as proteases, are enzymes that break down proteins into smaller peptides or amino acids. Examples include pepsin and trypsin, which play crucial roles in protein digestion.

2. **Identifying the Enzymes**: The question presents us with several enzymes: pepsin, trypsin, erypsin, and renin. We need to determine which of these is not a proteolytic enzyme.

3. **Analyzing Each Option**:
- **Pepsin**: This is a well-known proteolytic enzyme that digests proteins in the stomach.
- **Trypsin**: Another proteolytic enzyme, trypsin is produced in the pancreas and continues protein digestion in the small intestine.
- **Erypsin**: This is also a proteolytic enzyme that acts in the intestine to further digest proteins.
- **Renin**: Renin is not a proteolytic enzyme; it is an enzyme involved in the regulation of blood pressure and fluid balance, primarily acting on angiotensinogen in the kidneys.

4. **Conclusion**: Based on the analysis, the enzyme that is not a proteolytic enzyme is **renin**.

5. **Answering the Second Part of the Question**: The second part of the question asks which enzyme belongs to the class of pepsin and trypsin. Since pepsin and trypsin are both proteolytic enzymes, the correct answers for this part would be pepsin, trypsin, and erypsin.

**Final Answers**:
- The enzyme that is not a proteolytic enzyme: **Renin**
- The enzymes that belong to the class of pepsin and trypsin: **Pepsin, Trypsin, Erypsin**

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