While proposing the double helical structure for DNA, Watson and Crick had immediately proposed a scheme for replication of DNA. The scheme suggested that the two strands would separate and act as a template for the synthesis of new complementary strands. After the completion of replication, each DNA molecule would have one parental and one newly synthesised strand. This scheme was termed as semiconservative DNA replication. In eukaryotes, the replication of DNA takes place at S-phase of the cell-cycle. The replication of DNA and cell division cycle should be highly coordinated
The major ingredients involved in DNA replication are as follows:
RNA Primer: Initiator of DNA synthesis
DNA Polymerase I: It removed the RNA Primer and replace with DNA. Further it polymerise the DNA fragment. It always work in 5’ to 3’ direction.
DNA ligase: to join the okazaki fragments.
Helicase: it unwind the double helical structure.