What is the role of helicase in DNA replication?

What is the role of helicase in DNA replication?

• A. Pries apart the double strands of DNA
• B. Reads DNA sequences
• C. Joins Okazaki fragments
• D. Synthesizes RNA primer

Answer: (D)

Helicase acts as the unwinding motor at the replication fork. It uses energy from ATP to break the hydrogen bonds between the paired bases, prying the two strands apart so each serves as a template for copying. This separation creates the single-stranded templates that DNA polymerases need to synthesize new DNA strands. So, the key idea is that helicase's job is to open up the double helix, not to read sequences, synthesize RNA primers, or join fragments. The synthesis of RNA primers is done by primase, DNA polymerase reads the template and builds the new strand, and ligase seals gaps between Okazaki fragments on the lagging strand.

Helicase acts as the unwinding motor at the replication fork. It uses energy from ATP to break the hydrogen bonds between the paired bases, prying the two strands apart so each serves as a template for copying. This separation creates the single-stranded templates that DNA polymerases need to synthesize new DNA strands.

So, the key idea is that helicase's job is to open up the double helix, not to read sequences, synthesize RNA primers, or join fragments. The synthesis of RNA primers is done by primase, DNA polymerase reads the template and builds the new strand, and ligase seals gaps between Okazaki fragments on the lagging strand.