Describe the Process of DNA Replication

During DNA Replication, the existing molecule gets replicated, resulting in two semi-conservative DNA molecules. The enzyme helicase unwinds and unzips the double helix of the DNA, while topoisomerase moves ahead of helicase, relieving the strain and tension of this action, and single-stranded binding proteins prevent the strands from rewinding. As the double helix is being unwinded, DNA primase adds short RNA primers two both of the separated strands. On the leading strand, DNA polymerase III adds free nucleotides based on complimentary base pairing ( Adenine & Thymine; Guanine & Cytosine) in a 5' to 3' direction, forming a continuous new strand.On the lagging strand, DNA primase adds several RNA primers, as the movement of DNA polymerase will be in the opposite direction of helicase, due to the anti-parallel nature of DNA strands. Subsequently, DNA polymerase III adds free nucleotides to the primers, creating several short segments called Okazaki fragments. DNA polymerase I then replaces the RNA primers on both strands with DNA, followed by DNA ligase joining the Okazaki fragments together. Once replication is completed, the enzymes detach and the DNA molecules recoil.

Answered by Biology tutor

2483 Views

See similar Biology IB tutors

Related Biology IB answers

All answers ▸

Compare how pyruvate is used in human cells when oxygen is available and when oxygen is not available.


List three differences and three similarities between eukaryotic and prokaryotic cells


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


What is endosymbiotic theory?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences