Question

Which enzyme is responsible for the unwinding of DNA during replication?

• A. DNA polymerase
• B. DNA ligase
• C. DNA helicase
• D. RNA primase

Hint:

Helicase unwinds the helix, creating templates for new DNA strands to be synthesized during replication!

Answer 1

The Correct Option is C

In the process of DNA replication, the double-stranded DNA molecule needs to be unwound into two single strands to allow each strand to be copied. This unwinding is essential for the replication machinery to access the DNA bases and create a complementary strand.

The enzyme responsible for the unwinding of DNA is DNA helicase. DNA helicase binds to the DNA at the replication fork and uses energy derived from ATP hydrolysis to break the hydrogen bonds between the complementary base pairs. This action separates the two strands, creating two single-stranded DNA templates.

Let's briefly examine each of the other options to understand why they are not involved in the unwinding process:

• DNA polymerase: This enzyme synthesizes the new DNA strand by adding nucleotides to the growing chain, complementary to the template strand.
• DNA ligase: This enzyme joins Okazaki fragments on the lagging strand by forming phosphodiester bonds.
• RNA primase: This enzyme synthesizes a short RNA primer that provides a starting point for DNA polymerase.

Thus, among the given options, DNA helicase is specifically responsible for the unwinding of the DNA during replication.