Flashcards in Cell bio Deck (12):
What is the function of topoisomerases?
reduce DNA supercoiling by introducing breaks, **negative coiling** and ligation of the breaks
What are two major features of heterocromatin? What is the key consequence of these features?
heavily methylated DNA
low transcriptional activity
What is more likely to introduce faulty repair, double or single stranded DNA breaks?
hereditary non-polyposis colorectal cancer is associated with impaired _____
what enzyme is responsible for unwinding the double helix?
what removes supercoils in prokaryotic DNA replicaiton?
topoisomerase II (DNA gyrase)
what facilitates the stabilization of unwound template strands of DNA during prokaryotic DNA replication?
dingle stranded DNA-binding proteins
what enzyme synthesis the RNA during prokaryotic DNA replication?
primase (aka RNA polymerase)
what facilitatees 5' to 3' DNA synthesis and also has 3' to 5' exonuclease "proofreading" activity during prokaryotic DNA replication?
DNA polimerase I and III
What removes teh RNA primer (5' to 3' exonuclease acvity) and replaces it with DNA during prokaryotic DNA replication??
DNA polimerase I
what joinds the okazaki graments (lagging strand) during prokaryotic DNA replication?