Which enzyme breaks the hydrogen bonds during replication?

Helicase

Explanation:

In the process of DNA replication, the enzyme helicase breaks the hydrogen bonds between the base pairs of the DNA to "unzip" or"unwind it. When the double-strand split, each strand will serve as a template for a complementary strand to match up with it and each will form a new double-helix, itdentical to the orginal double strand.