Which of the following statement is not true about enzyme inhibitors ?

Options

A. inhibit the catalytic activity of the enzyme
B. Prevent the binding of substrate
C. Generally a strong covalent bond is formed between an inhibitor and an enzyme
D. Inhibitors can be competitive or non-competitive

Explanation

To determine which statement is not true about enzyme inhibitors, we will analyze each option provided:

1. **Inhibit the catalytic activity of the enzyme**:
- This statement is true. Enzyme inhibitors are known to reduce or completely halt the catalytic activity of enzymes. They achieve this by binding to the enzyme and preventing it from catalyzing its reaction.

2. **Prevent the binding of substrate**:
- This statement is also true. Some enzyme inhibitors work by blocking the active site of the enzyme, preventing the substrate from binding. This is a common mechanism of inhibition.

3. **Generally a strong covalent bond is formed between an inhibitor and an enzyme**:
- This statement is not true. While some inhibitors can form covalent bonds with enzymes, most enzyme inhibitors bind through weaker interactions such as hydrogen bonds, ionic bonds, or van der Waals forces. Strong covalent bonds would imply a permanent inhibition, which is not characteristic of most enzyme inhibitors.

4. **Inhibitors can be competitive or non-competitive**:
- This statement is true. Enzyme inhibitors can be classified as competitive, which compete with the substrate for the active site, or non-competitive, which bind to an enzyme at a different site and reduce its activity regardless of substrate binding.

Based on this analysis, the statement that is not true about enzyme inhibitors is the third option: "generally a strong covalent bond is formed between an inhibitor and an enzyme."

### Summary of the Solution:
- The first statement is true.
- The second statement is true.
- The third statement is not true (correct answer).
- The fourth statement is true.