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 solve the question of 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 is responsible for the breakdown of starch into simpler sugars (maltose).
- **Involvement in Digestion**: Yes, it is involved in the digestion of carbohydrates.

2. **Trypsinogen**:
- Trypsinogen is an inactive precursor (zymogen) secreted by the pancreas. It is activated to trypsin in the small intestine, where it helps in the digestion of proteins by breaking them down into peptides and amino acids.
- **Involvement in Digestion**: Yes, once activated to trypsin, it is involved in the digestion of proteins.

3. **Pepsin**:
- Pepsin is an enzyme present in gastric juice and is active in the stomach. It breaks down proteins into smaller peptides.
- **Involvement in Digestion**: Yes, it is involved in the digestion of proteins.

4. **Lysozyme**:
- Lysozyme is an enzyme found in saliva and has antibacterial properties. It helps to kill bacteria but does not participate in the breakdown of food molecules.
- **Involvement in Digestion**: No, it is not involved in digestion.

5. **Lipase**:
- Lipase is an enzyme that breaks down fats (lipids) into fatty acids and glycerol. It is primarily secreted by the pancreas and acts in the small intestine.
- **Involvement in Digestion**: Yes, it is involved in the digestion of fats.

6. **Rennin**:
- Rennin (or chymosin) is an enzyme that curdles milk and is primarily found in young mammals. It is not present in adults.
- **Involvement in Digestion**: No, it is not involved in digestion in adults.

Now, let's summarize the involvement of each enzyme in digestion:

- Salivary Amylase: Yes
- Trypsinogen: Yes (once activated to trypsin)
- Pepsin: Yes
- Lysozyme: No
- Lipase: Yes
- Rennin: No

**Total Involved in Digestion**: 4 enzymes (Salivary Amylase, Trypsinogen, Pepsin, Lipase)

Therefore, the answer to the question is **4**.

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