Which is common among Amylase, rennin and tryosin?

Options

A. All are proteins
B. All act at a pH lower than 7
C. All are proteolytic enzymes
D. All are produced in stomach

Answer

To determine what is common among amylase, renin, and trypsin, we can analyze each enzyme based on their characteristics and functions.

### Step-by-Step Solution:

1. **Identify the Enzymes**:
- **Amylase**: This enzyme is responsible for breaking down carbohydrates. It is found in saliva (salivary amylase) and in the pancreas (pancreatic amylase).
- **Renin**: This enzyme is primarily found in infants and is involved in the digestion of milk proteins. It is a proteolytic enzyme, meaning it breaks down proteins.
- **Trypsin**: This enzyme is produced in the pancreas and also functions as a proteolytic enzyme, breaking down proteins into smaller peptides.

2. **Analyze the Options**:
- **All are proteins**: Amylase, renin, and trypsin are all enzymes, which are proteins.
- **All act at a pH lower than 7**: This is not true for all three; for example, amylase functions optimally at a neutral pH (around 7).
- **All are proteolytic enzymes**: Only renin and trypsin are proteolytic enzymes. Amylase does not fall into this category as it digests carbohydrates.
- **All are produced in the stomach**: This is incorrect; while renin is produced in the stomach of infants, amylase is produced in the salivary glands and pancreas, and trypsin is produced in the pancreas.

3. **Conclusion**:
The common characteristic among amylase, renin, and trypsin is that **all are proteins**.

### Final Answer:
**All are proteins.**