What function does primase serve in DNA replication?

What function does primase serve in DNA replication?

• A. It unwinds the DNA double-helix
• B. It joins RNA nucleotides to make the primer
• C. It adds complementary nucleotides to the growing strand
• D. It stabilizes the unwound DNA strands

Answer: (B)

Primase plays a crucial role in DNA replication by synthesizing a short RNA primer. This primer is necessary because DNA polymerases, the enzymes responsible for synthesizing new DNA strands, can only add nucleotides to an existing strand of nucleic acid. Hence, the primer provides the starting point needed for DNA polymerase to begin adding DNA nucleotides. This initial RNA primer is typically about 5 to 10 nucleotides long and complementary to the DNA template strand. Once the primer is in place, DNA polymerase can attach to it and start elongating the new DNA strand by adding complementary DNA nucleotides. Understanding the function of primase clarifies the overall process of DNA replication since it signifies the transition between the initiation of replication and the actual elongation of the new DNA strand.

Primase plays a crucial role in DNA replication by synthesizing a short RNA primer. This primer is necessary because DNA polymerases, the enzymes responsible for synthesizing new DNA strands, can only add nucleotides to an existing strand of nucleic acid. Hence, the primer provides the starting point needed for DNA polymerase to begin adding DNA nucleotides.

This initial RNA primer is typically about 5 to 10 nucleotides long and complementary to the DNA template strand. Once the primer is in place, DNA polymerase can attach to it and start elongating the new DNA strand by adding complementary DNA nucleotides.

Understanding the function of primase clarifies the overall process of DNA replication since it signifies the transition between the initiation of replication and the actual elongation of the new DNA strand.