Q. The enzyme which catalyzes the unwinding of DNA helix during replication is ____:
Answer: Helicase
Notes: A type of helicase enzyme called DNA helicase catalyzes the unwinding of the DNA helix at the time of replication. It uses the energy released through hydrolysis of ATP (Adenosine triphosphate) to break the hydrogen bonds between the two strands. The enzyme is needed to separate the two strands of DNA also during transcription and DNA repair. Topoisomerase prevents rewinding of strands after halicase action.