Bio 2 - DNA Replication, Mutation And Repair Flashcards
Which protein unwinds the DNA in DNA replication?
Helicase.
What protein stabilizes the single-stranded DNA once it has been unwind?
Single-strand binding protein.
What does Topoisomerase do?
When the DNA is being unwind, the downstream part that has not been unwind yet gets supercoiled. This protein relieves the supercoil so it does not tangle up the DNA downstream.
Which class of antibiotics inhibits prokaryotic topoisomerase?
Fluoroquinolones.
Which class of drugs target eukaryote topoisomerase?
Etoposide. It is an anti-neoplastic drug.
Which auto antibody targets Topoisomerase and for which disease?
It is Anti-Scl-70, associated with Diffuse scleroderma (not CREST scleroderma).
What is an RNA primer?
A strand of RNA needed to initiate the actual replication after the strand has been unwind. In prokaryotes, RNA primer has to be made by Primase.
What does DNA polymerase III do?
It replicates the DNA in the Leading and Lagging strand in prokaryotes.
How is replication taking place in the Leading strand?
From 5’ to 3’ in a continuous manner.
How is DNA replicated in the Lagging strand?
Goes from 5’ to 3’ in fragments (Okazaki fragments); Primase keeps making more RNA primer for every fragment.
What does DNA polymerase I do?
It removes the RNA primer laid down in the fragment to replace it with real DNA.
Which protein ties the Okazaki fragments together once the RNA primer has been removed?
DNA ligase.
Who makes the Primer in Eukaryotes?
DNA polymerase alpha.
Who builds the Okazaki fragments on the lagging strand in Eukaryotes?
DNA polymerase alpha.
Which protein builds the DNA in the Leading strand in Eukaryotes?
DNA polymerase delta.
