Answer:
Explanation:
DNA polymerase is an enzyme that helps in the synthesis of new strands of DNA. It is found in both prokaryote and eukaryotes. In prokaryotes, there are 3 types of DNA polymerase and more DNA polymerase found in eukaryotes.
The 3 types of DNA polymerase are DNA polymerase I, DNA polymerase II, DNA polymerase III. The DNA pol I and DNA pol II helps in DNA repair rather than DNA replication. The DNA pol III is the major enzyme that initiates the replication.
DNA polymerase III is a multisubunit enzyme that functions as a dimer of these multiple subunits. The DNA polymerase enzyme has 3 significant enzymatic activities -
All DNA polymerase direct the synthesis of DNA from 3' to 5' end.
It possesses 3' to 5' exonuclease activity. It also helps in proofreading activity by replacing the incorrect nucleotides with the correct base sequence.
Some DNA polymerase has a 5' to 3' exonuclease activity. It is found in the lagging strand.
DNA polymerase is not able to initiate DNA synthesis alone. They need a free 3' end, where the enzyme can add new nucleotides. It means they require 2 primers to initiate the DNA replication in both the direction.
The strands act as complementary to the DNA polymerase. The DNA polymerase adds new strands continuously in 5' to 3' direction in the leading strand. While in lagging strand short fragments of DNA formed. Later they attached by DNA ligase.
DNA polymerase also needs RNA polymerase in some cases to start replication. Such a process is called reverse transcription.
