• DNA replication is catalyzed by DNA polymerase which needs an RNA primer to start the process.
• DNA primase synthesizes RNA primer on DNA strand.
• The primer binds as the starting point for DNA replication and synthesis.
• DNA polymerase adds nucleotides to the 3’ end of the growing strand (5' to 3' direction)
• In eukaryotic cells, primary polymerases involved in DNA replication are polymerases alpha, delta and epsilon.
• Since DNA is double-stranded, only one strand will support the 5' to 3' polymerization of DNA polymerase.
• Therefore, DNA synthesis on the leading strand is continuous while DNA synthesis on the lagging strand is discontinuous where:
• The lagging strand grows in the same 5' to 3' direction as the leading strand (in the same direction as the Replication Fork).
• However, DNA is added as short fragments (Okazaki fragments).
• The lagging strand begins replication by binding with multiple primers.
• DNA polymerase then adds pieces of Okazaki fragments to the strand between primers.

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