What role does helicase play in DNA replication?

Helicase is an essential enzyme in DNA replication, primarily responsible for unwinding the DNA double helix. During replication, the two strands of the DNA molecule must be separated to allow for the synthesis of new complementary strands. Helicase does this by breaking the hydrogen bonds between the nucleotide bases that hold the two strands together, effectively "unzipping" the DNA. This unwinding is crucial because it creates single-stranded templates that are necessary for the next steps in replication, including the synthesis of new strands by DNA polymerase. Without helicase, the DNA strands would remain tightly coiled and inaccessible for replication.