What is the primary function of helicase during DNA replication?

The primary function of helicase during DNA replication is to unwind the double helix by breaking the hydrogen bonds between the complementary base pairs of the DNA strands. This activity is crucial because it separates the two strands of the DNA, allowing each strand to serve as a template for the synthesis of new strands. By unwinding the DNA at the replication fork, helicase facilitates access for other enzymes, such as DNA polymerase, which can then synthesize new DNA based on the sequence of the template strands. This unwinding action is essential for the overall process of DNA replication, ensuring that the double-stranded DNA can be replicated accurately and efficiently.

The roles described in the other choices pertain to different enzymes involved in DNA replication. Synthesizing RNA primers is a function of primase, which lays down short RNA sequences that assist in initiating DNA synthesis. Preventing single strands from re-annealing is typically the role of single-strand binding proteins, which stabilize the unwound strands during replication. Sealing nicks in the DNA backbone is performed by DNA ligase, which connects Okazaki fragments on the lagging strand. Each of these enzymes contributes to a specific function in the overall process of DNA replication, but helicase's unique role in