What is the role of DNA polymerase in DNA replication?

DNA polymerase is an enzyme that plays a crucial role in DNA replication.

During DNA replication, the double-stranded DNA molecule unwinds and separates into two strands. Each strand serves as a template for the synthesis of a new complementary strand. DNA polymerase is responsible for adding nucleotides to the growing strand in a specific order, according to the base-pairing rules (A-T and C-G).

DNA polymerase can only add nucleotides to the 3' end of a pre-existing strand, so a short RNA primer is first synthesized by another enzyme called primase. DNA polymerase then extends the RNA primer by adding DNA nucleotides, one at a time, to the 3' end of the growing strand. As the polymerase moves along the template strand, it reads the sequence of nucleotides and adds complementary nucleotides to the new strand.

DNA polymerase also has a proofreading function, which allows it to detect and correct errors that may occur during replication. If a mismatched nucleotide is added, the polymerase can remove it and replace it with the correct nucleotide before continuing with synthesis.

In summary, DNA polymerase is essential for DNA replication as it adds nucleotides to the growing strand and ensures the accuracy of the newly synthesized DNA molecule.