Replication occurs during the S Phase of the cell cycle. Initiator proteins begin the process. The strands are separated by the enzyme helicase. DNA polymerase begins replicating the leading strand in the 5' to 3' direction since DNA is antiparallel. The other strand, or the lagging strand, uses primase to copy the strand in the 5' to 3' direction but it only does a few nucleotides at a time. These fragments are called Okazaki fragments and they are ligated by an enzyme called ligase. …
