What is the function of helicase in DNA replication?

Helicase plays a crucial role in DNA replication by unwinding the double-stranded DNA. During the replication process, the two strands of DNA must separate to allow the replication machinery to access each strand as a template for synthesizing new complementary strands. Helicase accomplishes this by breaking the hydrogen bonds between the nucleotide base pairs, effectively separating the two strands while moving along the DNA molecule. This unwinding action is vital for the initiation of replication, enabling other enzymes like DNA polymerase to synthesize new DNA strands.

The other functions mentioned do not pertain to helicase. For example, while supercoiling is an important aspect of DNA structure and function, it is managed by other enzymes such as topoisomerases. The connection of Okazaki fragments, which are short sequences of DNA synthesized discontinuously on the lagging strand during replication, is performed by ligase, not helicase. The destruction of bacterial cell walls is irrelevant to DNA replication and describes a function related to antibiotics rather than DNA processes. Thus, the unwinding of DNA strands by helicase is essential for enabling the replication process to occur correctly.