Understanding:
• Helicase unwinds the double helix and separates the two strands by breaking hydrogen bonds
• DNA polymerase links nucleotides together to form a new strand, using the pre-existing strand as a template
DNA replication is a semi-conservative process whereby pre-existing strands act as templates for newly synthesised strands
The process of DNA replication is coordinated by two key enzymes – helicase and DNA polymerase
Helicase
- Helicase unwinds the double helix and separates the two polynucleotide strands
- It does this by breaking the hydrogen bonds that exist between complementary base pairs
- The two separated polynucleotide strands will act as templates for the synthesis of new complementary strands
DNA Polymerase
- DNA polymerase synthesises new strands from the two parental template strands
- Free deoxynucleoside triphosphates (nucleotides with 3 phosphate groups) align opposite their complementary base partner
- DNA polymerase cleaves the two excess phosphates and uses the energy released to link the nucleotide to the new strand
DNA Replication Summary
DNA Replication Animation