Which enzyme unwinds the DNA double helix during replication?

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Multiple Choice

Which enzyme unwinds the DNA double helix during replication?

Explanation:
Unwinding the DNA double helix is the first critical step in replication. DNA helicase binds to the DNA at the origin and uses energy from ATP hydrolysis to break the hydrogen bonds between complementary bases, separating the two strands and forming the replication fork. This opening allows the template strands to be exposed for copying. Other enzymes have different roles: DNA polymerase synthesizes the new strand by adding nucleotides to a primer; primase creates the RNA primer to start synthesis; ligase seals nicks between fragments on the lagging strand. Stabilizing proteins keep the unwound strands from snapping back together. Because its job is to separate the strands so replication can proceed, helicase is the enzyme that unwinds the DNA double helix.

Unwinding the DNA double helix is the first critical step in replication. DNA helicase binds to the DNA at the origin and uses energy from ATP hydrolysis to break the hydrogen bonds between complementary bases, separating the two strands and forming the replication fork. This opening allows the template strands to be exposed for copying. Other enzymes have different roles: DNA polymerase synthesizes the new strand by adding nucleotides to a primer; primase creates the RNA primer to start synthesis; ligase seals nicks between fragments on the lagging strand. Stabilizing proteins keep the unwound strands from snapping back together. Because its job is to separate the strands so replication can proceed, helicase is the enzyme that unwinds the DNA double helix.

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