How are the enzymes DNA polymerase and DNA helicase are involved with replication and what do they do?
During DNA replication, a replisome, which is a complex of enzymes involved in replicating DNA attaches to the DNA. The first of these enzymes is helicase, which unwinds and unzips the DNA by breaking the H bonds between the nitrogenous bases. Since the nucleotides must have a sugar to attach to, Primase builds a short segment of RNA (which is about 10 N bases long). This is called a primer and is always built at the origin of replication. DNA polymerase 3 is the enzyme that links the nucleotides together and builds new strand once the RNA primer is in position. The DNA polymerase can only work on a template strand that runs in the 3’→5’ direction, therefore it builds a new molecule in 5’→3’ direction. DNA polymerase 1 removes primer and replaces it with DNA nucleotides and also proofreads.
