DNA Rep and Repair Flashcards
What does exonuclease do?
allows DNA pol to back up and fix mistakes in txn
common DNA damage produced by UV radiation
covalent linkage between adjacent pyrimidines. - removed during replication and will cause frame shift or point mutation
What does EthBro do to DNA
intercalates between nts and makes it impossible to transcribe highly carcinogenic
why is methylated cytosine bad?
it causes a T to be paired with a G- glycosylase recognizes and removes the T but it still creates a frameshift mutation upon replication
What does photolyase do?
it uses light to fix thymine dimers
Cause of Cockayne Syndrome
Transcription coupled repair mechanism doesnt work because the RNA pol is unable to talk to the DNA pol, leading to permanent stalling of RNA pol at sites of damage.
What causes hereditary nonpolyposis colorectal cancer?
nonfunctional or partially functional Mismatch Excision Repair Complex (MER) because it cant recognizes nt mismatches and mutation occurs over a lifetime
dyskeratosis congenita
have mutant telomerase RNA
premature aging
die because of loss of bone marrow (all stem cells, cant renew)
