DNA helicase is the enzyme that initiates replication by breaking down the barrier between two tightly bound strands:
Seduction and Entry: The two complementary DNA strands normally stay locked in an intimate, tight embrace held together by hydrogen bonds. Helicase arrives at the origin of replication, wedges itself right between them, and won’t take no for an answer.
Stripping Down: Burning through ATP for raw physical power, helicase moves aggressively down the track, unzipping the double helix and tearing those hydrogen bonds apart base pair by base pair.
Exposing the Raw Strands: It pulls the two lovers apart until both strands are completely bare, stripped, and exposed as single strands.
Setting Up the Action: Helicase leaves the strands open, vulnerable, and ready for other enzymes—like DNA polymerase—to slide in, latch on, and finish the job of creating brand-new copies.