Assertion : The inhibition of activity of succinic dehydrogenase by malonate which closely resembles the substrate succinate in structure is the example of competitive inbhibition.
Reason : Competitive inhibition is the inhibition of enzyme activity when inhibitor closely resembles the substrate, in its molecular structre.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that malonate inhibits the activity of succinic dehydrogenase, and this inhibition is an example of competitive inhibition.
- Competitive inhibition occurs when an inhibitor (malonate) competes with the substrate (succinate) for binding to the active site of the enzyme (succinic dehydrogenase).

2. **Understanding the Reason**:
- The reason explains that competitive inhibition happens when the inhibitor closely resembles the substrate in its molecular structure.
- This resemblance allows the inhibitor to bind to the enzyme's active site, preventing the actual substrate from binding.

3. **Analyzing the Relationship**:
- The assertion is correct because malonate indeed resembles succinate and inhibits succinic dehydrogenase in a competitive manner.
- The reason is also correct as it accurately describes the mechanism of competitive inhibition.

4. **Conclusion**:
- Since both the assertion and the reason are correct, and the reason provides a valid explanation for the assertion, we conclude that both statements are true.

### Final Answer:
Both the assertion and the reason are correct, and the reason given is the correct explanation for the assertion.

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