What is the primary function of Helicase in DNA replication?

The primary function of helicase during DNA replication is to unwind the DNA double helix. This is a crucial step in the process because DNA is structured as a double-stranded molecule, with two strands wrapped around each other. Before new strands can be synthesized, the two strands need to be separated to allow the essential replication machinery access to the DNA template.

Helicases achieve this by breaking the hydrogen bonds that hold the base pairs of the two strands together. As helicase moves along the DNA molecule, it unwinds the helix, creating two single-stranded templates that serve as guides for the synthesis of new complementary strands. This action is essential for proper DNA replication, ensuring that each daughter cell receives an accurate copy of the genetic material.

Other functions like synthesizing new DNA strands or gluing fragments together are carried out by different enzymes, such as DNA polymerase and DNA ligase, respectively, while DNA repair processes are mediated by a variety of repair enzymes, not helicase. Thus, the unwinding action of helicase is fundamental to the initiation of replication, making it the correct answer.