Most of the enzymes when secreted are in inactive form (called proenzymes or zymogens) otherwise they will mainly destroy

Options

A. cell proteins
B. cell DNA
C. cell mitochondriane
D. cell wall and membrane

Answer

### Step-by-Step Solution

1. **Understanding Proenzymes/Zymogens**: Enzymes are biological catalysts that speed up chemical reactions in the body. However, when secreted, many enzymes are in an inactive form known as proenzymes or zymogens. This is crucial for preventing premature activation.

2. **Examples of Proenzymes**: In the stomach, specific enzymes such as pepsinogen (the inactive form of pepsin) and prorenin are secreted in their inactive forms. This prevents them from digesting proteins or damaging tissues before they reach their target site.

3. **Activation Process**: Once these proenzymes reach the acidic environment of the stomach (due to hydrochloric acid, HCl), they undergo a transformation into their active forms. For example, pepsinogen is converted to pepsin, which can then aid in digestion.

4. **Consequences of Active Enzymes**: If these enzymes were secreted in their active forms, they could begin digesting the tissues of the stomach itself. This could lead to severe damage to the stomach lining, resulting in ulcers or other gastrointestinal issues.

5. **Protection Mechanism**: The secretion of enzymes in an inactive form serves as a protective mechanism. It ensures that the enzymes only become active when they are in the appropriate environment (like the stomach) and at the right time, thus preventing self-digestion of the cells that produce them.

6. **Conclusion**: Therefore, the main reason for the secretion of enzymes in their inactive form is to prevent damage to the cell membranes and walls of the stomach and other tissues. If active, these enzymes could destroy the very cells that produce them.

### Final Answer
The enzymes are secreted in inactive form (proenzymes or zymogens) to prevent them from destroying the cell membranes and walls of the stomach.

---