Statins are competitive inhibitors of

Options

A. Streptokinase
B. HMG COA reductase
C. Pectinase
D. Cellulase

Answer

**Step-by-Step Solution:**

1. **Understanding Statins**: Statins are a class of drugs that are primarily used to lower cholesterol levels in the blood. They are known to be effective lipid-lowering agents.

2. **Mechanism of Action**: Statins work by inhibiting certain enzymes in the body. Specifically, they act as competitive inhibitors, meaning they compete with the substrate for binding to the enzyme's active site.

3. **Identifying the Target Enzyme**: The primary target enzyme for statins is HMG-CoA reductase. This enzyme is crucial in the cholesterol biosynthesis pathway, as it catalyzes the conversion of HMG-CoA to mevalonate, a precursor of cholesterol.

4. **Evaluating the Options**:
- **Streptokinase**: An enzyme that helps dissolve blood clots, not related to cholesterol metabolism.
- **HMG-CoA Reductase**: Correct answer, as it is the enzyme that statins inhibit.
- **Spectinase**: An enzyme that breaks down spectinomycin, not related to cholesterol.
- **Cellulase**: An enzyme that breaks down cellulose, found in plant cell walls, also not related to cholesterol.

5. **Conclusion**: Based on the above analysis, the correct answer is that statins are competitive inhibitors of **HMG-CoA reductase**.

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