Explain DNA replication (SL).

DNA replication is the process through which two new strands of DNA are synthesized from the original molecule and predominantly occurs in the S phase of the cell cycle prior to mitosis. To put it simply, we first find one double-stranded helix-shaped DNA molecule, where Adenine must always binds to Thymine and Cytosine to Guanine through hydrogen bonds (H-bonds). In order to initiate the process, an enzyme known as DNA helicase unzips and separates the DNA strands by breaking these H-bonds. The two strands now act as tempates for the new strands to be synthesized. This process is done through the help of the enzyme DNA polymerase, which attaches free deoxynucleoside triphosphates (nucleotides with three phosphate groups) to the parent strands, following the A-T and C-G rule. Two of those three phosphate groups are used to fuel the reaction. 

DNA replication is a semi-conservative process, which means that when DNA is replicated through the actions of helicase and DNA polymerase, the newly formed strands will be identical to the original strands separated from the template. In other words, each new double-stranded DNA moelcule will have one strand from the original molecule and one newly synthesized strand. 

Answered by Jordi M. Biology tutor

1075 Views

See similar Biology IB tutors
Illustration of a video tutorial

Need help with Biology?

One to one online tuition can be a great way to brush up on your Biology knowledge.

Have a Free Meeting with one of our hand picked tutors from the UK’s top universities

Find a tutor

Related Biology IB answers

All answers ▸

How does muscle contraction take place?


What steps occur during glycolysis?


Explain the process of Translation.


Why was the experiment on DNA done by Meselson and Stahl strong evidence that DNA replication is semi-conservative?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2022

Terms & Conditions|Privacy Policy