Unwinding of DNA creates tension which is released by enzyme

Options

A. Helicase
B. Topoisomerase
C. Primase
D. Ligase

Answer

**Step-by-Step Solution:**

1. **Understanding DNA Replication**: DNA replication involves the unwinding of the double helix structure of DNA to allow for the synthesis of new strands.

2. **Identifying the Role of Helicase**: The enzyme helicase is responsible for unwinding the DNA strands. It does this by breaking the hydrogen bonds between the base pairs, which requires energy from ATP.

3. **Recognizing the Tension Created**: As the DNA strands are unwound, tension is created in the DNA molecule. This tension can lead to supercoiling, which can hinder the replication process.

4. **Function of Topoisomerase**: To relieve this tension, the enzyme topoisomerase comes into play. It prevents the coiling of the DNA strands by making transient breaks in the DNA. This allows the strands to rotate and release the built-up tension.

5. **Excluding Other Options**:
- **Primase** is involved in synthesizing RNA primers necessary for DNA replication but does not relieve tension.
- **Ligase** is responsible for joining DNA fragments together but does not play a role in unwinding or relieving tension.

6. **Conclusion**: The enzyme that releases the tension created by the unwinding of DNA during replication is **topoisomerase**.

**Final Answer**: The tension created by the unwinding of DNA is released by the enzyme **topoisomerase**.

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