Please briefly describe the three activities of DNA polymerase I.Please answer it in english

Please briefly describe the three activities of DNA polymerase I.Please answer it in english
Please briefly describe the three activities of DNA polymerase I.Please answer it in english

Please briefly describe the three activities of DNA polymerase I.Please answer it in english
DNA polymerase can add free nucleotides only to the 3' end of the
newly forming strand.This results in elongation of the newly forming
strand in a 5'-3' direction.No known DNA polymerase is able to begin a new chain (de novo).DNA polymerase can add a nucleotide only on to a pre-existing 3'-OH group,and,therefore,needs a primer at which it can add the first nucleotide.Primers consist of RNA and/or DNA bases.In DNA replication,the first two bases are always RNA,and are synthesized by another enzyme called primase.An enzyme known as a helicase
is required to unwind DNA from a double-strand structure to a
single-strand structure to facilitate replication of each strand
consistent with the semiconservative model of DNA replication.
It is important to note that the directionality
of the newly forming strand (the daughter strand) is opposite to the
direction in which DNA polymerase moves along the template strand.DNA
polymerase moves along the template strand in a 3'-5' direction,and the
daughter strand is formed in a 5'-3' direction.This difference enables
the resultant double-stranded DNA formed to be composed of two DNA
strands which are antiparallel to each other.
Error correction is a property of some,but not all,DNA polymerases.
This process corrects mistakes in newly synthesized DNA.When an
incorrect base pair is recognized,DNA polymerase moves backwards by one
base pair of DNA.The 3'-5' exonuclease activity of the enzyme allows the incorrect base pair to be excised (this activity is known as proofreading).Following base excision,the polymerase can re-insert the correct base and replication can continue forwards.
Various DNA polymerases are extensively used in molecular biology experiments.