Which of the following statement is correct about competitive inhibitors?

Options

A. The inhibitor does not resembles the substrate
B. The inhibitor competes with the substrate for the allosteric sites.
C. Inhibition of succinic hydrogenase by malonate which closely resembles the substrate succinate in structure is an example of it
D. this mechanism is used in the control of bacteria pathogens

Answer

To determine the correct statement about competitive inhibitors, let's analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Competitive Inhibition**:
- Competitive inhibitors are molecules that resemble the substrate and compete for binding to the active site of an enzyme. They have a similar shape and size to the substrate, allowing them to bind to the active site.

2. **Evaluating Each Statement**:
- **Statement 1**: "Inhibitor does not resemble the substrate."
- This statement is **incorrect**. Competitive inhibitors must resemble the substrate in order to compete for the active site.

- **Statement 2**: "Inhibitor competes with the substrate for the allosteric site."
- This statement is **incorrect**. Competitive inhibitors compete for the active site, not the allosteric site. Allosteric sites are distinct from the active site and are involved in non-competitive inhibition.

- **Statement 3**: "Inhibition of succinic dehydrogenase by malonate is an example of competitive inhibitor."
- This statement is **incorrect**. While malonate is a competitive inhibitor of succinate dehydrogenase, the question refers to "succinic hydrogenase," which is not a standard enzyme name. Therefore, this statement is misleading.

- **Statement 4**: "This mechanism is used in the control of bacterial pathogens."
- This statement is **correct**. Competitive inhibition is utilized in various antibacterial drugs, such as sulfa drugs, which inhibit bacterial enzymes by mimicking substrates.

3. **Conclusion**:
- The correct statement about competitive inhibitors is **Statement 4**: "This mechanism is used in the control of bacterial pathogens."