What are the enzymes involved at each stage during DNA replication?

The initial ‘unzipping’ stage is carried out by DNA helicase, to create a fork of DNA with exposed base pairs. DNA helicase works by breaking the hydrogen bonds between base pairs. On the leading strand, a short RNA primer synthesised by DNA primase binds to the 5’ end of the strand. DNA polymerase then binds to the DNA strand at the site of the primer and moves along the strand, adding complimentary base pairs in the 5’ to 3’ direction. On the lagging strand, multiple short RNA primers synthesised by DNA primase bind to the exposed base pairs, a short distance apart from each other. DNA polymerases then bind to each primer site and add complimentary base pairs in the 5’ to 3’ direction. These are called Okazaki fragments. DNA ligase then binds the Okazaki fragments together by connecting the sugar-phosphate backbones of each, to create a continuous new DNA strand through the formation of phosphodiester bonds.