lecture 5

Question 1

what disease is caused by mutations in DNA helicase

Answer 1

Werners syndrome - premature ageing

bloom syndrome - rare cancer

Question 2

what does the sliding clamp do

Answer 2

increases processivity of DNA polymerase

clamp loader and SC encircle DNA like a nut and bolt to help0 DNA polymerase move foreward

Question 3

what do single stranded binding proteins do

Answer 3

unlock hairpins straghtening out SSDNA

Question 4

what do topoisomers do

Answer 4

topoisomer 1 - cuts and reseals one strand - no ATP
topoisomer 2 - cuts and reseals both -ATP
helps prevent tension that would cause tangling

Question 5

what is in the Pre replicative complex

Answer 5

helicase loading proteins Cdc6 and Cdt1

Origin recognition complexhelicase Mcm2-7 binds

Question 6

what fixes gaps caused by RNA primase on l;agging strand

Answer 6

telomerase repliocates TTAGGG over and over so no important coding info is lost