DNA replication

• Semi-conservative replication:

  • The enzyme DNA helicase breaks the hydrogen bonds linking base pairs, unzipping hare DNA
  • Double helix separates and unwinds
  • Each exposed polynucleotide strand then acts as a template for complementary free nucleotides
  • Nucleotides are joined by a condensation reaction via DNA polymerase
  • Each new DNA molecule contains one strand of original material, one strand of new material
• Conservative replication:

  • incorrect model for DNA relipication
  • suggests the original molecule stays intact while a new replica is made
  • one strand would be entirely old material, another would be entirely new material