What are the different enzymes involved in replication and what do they do?

There are many enzymes which are crucial for replication. The first is helicase which unwinds the double helix at the replication fork. DNA gyrase then reduces the strain caused by the unwinding of the helix and ensures that no coils are formed. Single-stranded binding proteins then bind to the DNA strands to prevent them from re-annealing and to ensure that the lagging strand is not digested by nucleases. The next enzyme is primase which synthesizes the RNA primers needed to begin the formation of the new DNA strands. DNA polymerase III then synthesizes the new strands by adding nucleotides to the primer in a 5' to 3' direction. Next, DNA polymerase I removes the RNA primer and replaces it with DNA. Finally, on the lagging strand DNA ligase joins the ends of DNA segments and the Okazaki fragments.