How does DNA replication occur?

DNA normally exists in the cell as a double-stranded structure, comprising of two complementary strands that are held together by hydrogen bonds.

DNA replication involves two main steps. Firstly, the enzyme HELICASE breaks the hydrogen bonds holding the two strands together, causing the strands to separate. Next, one DNA POLYMERASE enzyme binds to each strand of DNA and, using the strand as a template, generates a complementary strand.

Once this process is complete, there are now two double-stranded DNA molecules. This is known as SEMI-CONSERVATIVE replication, as each new DNA molecule is made up of one old strand and one new strand.

Answered by Katharine H. Biology tutor

11496 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

What is semi-conservative replication?


Describe how negative feedback is used to control blood glucose concentration


Nitrate from fertiliser applied to crops may enter ponds and lakes. Explain how nitrate may cause the death of fish in fresh water.


Give a definition/explanation for the term 'phenotype'


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 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences