Which enzyme is used to synthesize new DNA strands by reading the template?

Which enzyme is used to synthesize new DNA strands by reading the template?

• A. DNA polymerase
• B. DNA ligase
• C. Primase
• D. Helicase

Answer: (A)

DNA polymerase is the enzyme that builds a new DNA strand by using the existing strand as a template. It reads the template and adds complementary nucleotides to the growing strand, synthesizing in the 5' to 3' direction and forming phosphodiester bonds. A primer is needed to start synthesis, and polymerase extends from that primer, ensuring correct base pairing (A with T, G with C). Other enzymes assist in replication—primase makes the RNA primer, helicase unwinds the DNA, and ligase seals fragments—but they don’t synthesize the new DNA strand themselves. DNA polymerase is the one that actually copies the template into a new DNA strand.

DNA polymerase is the enzyme that builds a new DNA strand by using the existing strand as a template. It reads the template and adds complementary nucleotides to the growing strand, synthesizing in the 5' to 3' direction and forming phosphodiester bonds. A primer is needed to start synthesis, and polymerase extends from that primer, ensuring correct base pairing (A with T, G with C). Other enzymes assist in replication—primase makes the RNA primer, helicase unwinds the DNA, and ligase seals fragments—but they don’t synthesize the new DNA strand themselves. DNA polymerase is the one that actually copies the template into a new DNA strand.