Which enzyme do not digests proteins and peptides in small intestine

Options

A. Pepsin
B. Trypsin
C. Chymotrypsin
D. Aminopeptidase

Answer

To determine which enzyme does not digest proteins and peptides in the small intestine, we can analyze the options provided:

1. **Pepsin**:
- Pepsin is an enzyme that is secreted by the gastric glands in the stomach.
- It functions optimally in an acidic environment (low pH) and is responsible for breaking down proteins into smaller peptides in the stomach, not the small intestine.

2. **Trypsin**:
- Trypsin is produced in the pancreas and is released into the small intestine.
- It works in an alkaline environment and is involved in the digestion of proteins and peptides.

3. **Chymotrypsin**:
- Chymotrypsin is also produced in the pancreas and acts in the small intestine.
- Similar to trypsin, it digests proteins and peptides in an alkaline environment.

4. **Aminopeptidase**:
- Aminopeptidase is an enzyme located in the small intestine that breaks down peptides into amino acids.
- It also functions in the small intestine and is involved in protein digestion.

After analyzing all the options, we can conclude that:

- **The enzyme that does not digest proteins and peptides in the small intestine is Pepsin** (option 1).

### Step-by-Step Solution:
1. Identify the enzymes listed in the options: Pepsin, Trypsin, Chymotrypsin, and Aminopeptidase.
2. Understand the function and location of each enzyme:
- Pepsin: Digests proteins in the stomach (acidic pH).
- Trypsin: Digests proteins in the small intestine (alkaline pH).
- Chymotrypsin: Digests proteins in the small intestine (alkaline pH).
- Aminopeptidase: Digests peptides in the small intestine (alkaline pH).
3. Determine which enzyme does not act in the small intestine: Pepsin.
4. Conclude that the correct answer is Pepsin (option 1).