Purpose of Replication
Ensures continuity of heredity information
Replication
Genetic info is copied, occurs before cell division, allows transmission of complete genomes from one generation to the next
Semi-conservative
Replicated DNA molecule contains one original strand and one new strand, the original acts as the blueprint
5 prime end
Phosphate terminus, nucleotides added to it
3 prime end
Hydroxyl terminus, DNA polymerase attaches to it
Anti Parallel
Orientation of DNA strands, run in opposite directions
5’-3’
Nucleotides can only be added in this direction
Leading Strand
Strand synthesized continuously
Lagging strand
Synthesized discontinuously (in fragments)
Helicase
Unwinds DNA strands
Topoisomerase
Relaxes the supercoil at the replication fork
Replication fork
Location where the 2 DNA strands are separated
DNA Polymerase
Enzyme responsible for synthesizing new DNA strands by adding nucleotides in the 5' to 3' direction during DNA replication. Attaches to the 3’ end and requires RNA primers to start synthesis.
Ligase
Joins the fragments on the lagging strand