3.1.5.2 DNA replication

semi-conservative replication

conserves one strand (template) and creates a new second DNA strand from free nucleotides

DNA helicase

unwinds DNA by breaking the hydrogen bonds between complementary base pairs

DNA polymerase

catalyses the condensation reaction joining adjacent nucleotides

Bond between two adjacent nucleotides

Phosphodiester bond

what the strand which is conserved acts as

a template

what binds to the exposed bases on the template strand

free nucleotides

anti parallel

DNA polymerase acts in reverse due to anti parallel strands on each side

DNA structure related to its function

-Two strands → both can act as templates for semi-conservative replication

-Hydrogen bonds between bases are weak → strands can be separated for replication

-Complementary base pairing → accurate replication

-Many hydrogen bonds between bases → stable/strong molecule

-Double helix with sugar phosphate backbone→ protects bases / hydrogen bonds

-Long molecule → store lots of genetic information (that codes for polypeptides)

-Double helix(coiled) → compact