Final answer:
Helicase opens the double-stranded DNA molecule by breaking the hydrogen bonds between the base pairs during DNA replication.
Step-by-step explanation:
Helicase plays a critical role in the process of DNA replication, particularly in relation to double-stranded DNA. It is responsible for opening the double-stranded DNA molecule by breaking the hydrogen bonds between the base pairs. This action creates a replication bubble and separates the DNA strands at the origin of replication. Helicase works alongside other enzymes like topoisomerase, single-stranded binding proteins, and primase to ensure successful replication of the DNA.