Semi-conservative replication

• Firstly, DNA helicase breaks the hydrogen bonds between the base pairs in DNA. This causes the double helix to separate it's two strands and unwind. Each exposed polynucleotide strand then acts as a template to which complementary free nucleotides can bind to via specific base pairs. Next, DNA polymerase catalyses the condensation reactions between adjacent nucleotides, creating phosphodiester bonds.
• Semi-conservative replication means that each of the new DNA molecules contains one of the original strands of DNA and one of the newly synthesised strands.