DNA replication Flashcards
What is helicase for
Unwinds and separates the DNA
What is single stranded binding proteins for
Stabilises the unwound strands
What is primase for
Synthesises RNA primers using the parental DNA as a template
In what direction is the leading strand SYNTHESIZED
5’ To 3’
What DNA polymerase continues on from RNA primers
3
DNA polymerases can’t do what? So what other protein has to do it
Can’t initiate so RNA primase has to initiate
The DNA polymerase will start from where
Continue from the 3’ end of the RNA primer
What happens when the DNA polymerase 3 reaches the RNA primer on the lagging strand
Detaches off
DNA Polymerase 1 does what
Replaces the RNA primer with DNA ie Uracil with Thymine
What does DNA Ligase do
Joins the new fragments together and proof reads
What does nuclease do?
DNA Cutting enzyme
Nucleotide excision repair uses what 3 things
Nuclease, Polymerase and Ligase
Are the replicated DNAs always shorter than the parent
Yes
Why are the daughter DNAs shorter than the parent
RNA primer can’t be replaced with DNA because there is no 3’ end Available for DNA polymerase to join
What are telomeres
Repetitive sequences at the ends of linear DNA molecules
