How many of the following enzymes are involved in digestion of food in adults?
(Salivary amylase , Trypsinogen , Pepsin, Lysozyme, Lipase, Rennin)

Options

A. 5
B. 3
C. 6
D. 4

Answer

To determine how many of the listed enzymes are involved in the digestion of food in adults, we will analyze each enzyme one by one.

1. **Salivary Amylase**:
- This enzyme is secreted in the saliva and begins the digestion of starch in the mouth. It is actively involved in the digestive process for adults.
- **Involvement in Digestion**: Yes

2. **Trypsinogen**:
- Trypsinogen is a pro-enzyme (inactive form) secreted by the pancreas. It is activated in the small intestine to form trypsin, which digests proteins.
- **Involvement in Digestion**: Yes

3. **Pepsin**:
- Pepsin is an enzyme that is active in the stomach and is responsible for breaking down proteins into peptides.
- **Involvement in Digestion**: Yes

4. **Lysozyme**:
- Lysozyme is an enzyme that has antibacterial properties and is found in saliva and other secretions. It does not play a role in the digestion of food.
- **Involvement in Digestion**: No

5. **Lipase**:
- Lipase is an enzyme that breaks down fats into fatty acids and glycerol. It is secreted by the pancreas and is involved in fat digestion in the small intestine.
- **Involvement in Digestion**: Yes

6. **Rennin**:
- Rennin (or chymosin) is an enzyme that curdles milk and is primarily found in infants. It is not present in significant amounts in adults.
- **Involvement in Digestion**: No

Now, let's summarize the findings:

- **Involved in Digestion**:
- Salivary Amylase
- Trypsinogen
- Pepsin
- Lipase

- **Not Involved in Digestion**:
- Lysozyme
- Rennin

Thus, the total number of enzymes involved in the digestion of food in adults is **4**.

### Final Answer: 4