DNA Repair Flashcards
What is direct reversal DNA repair?
DNA damage that can be directly reversesd
What are homology-repair dependent pathways?
pathways that can use the undamaged, complementary DNA strand to fix the other strand
What is excision repair?
repair that happens prior to DNA replication
What is post-replicative repair?
repair that happens during and after DNA replication
What is the mismatch repair pathway?
targets mismatched Watson-Crick base pairs that were not repaired by DNA polymerase proofreading during replication
What can cause double-strand breaks?
reactive oxygen species, ionizing radiation, UV light, or chemical agents
What two pathways can help in DSB repair?
homologous recombination and non-homologous end joining
What is homologous recombination?
process where one sister chromatid can help repair a DSB in the other
What is non-homologous end joining?
used to accomplish DSB repairs when cells are not actively growing or cycling through the cell cycle and dont have sister chromatids available
What is the main method if direct reversal in humans?
nucleotide excision
What two enzymes are required to accomplish homologous recombination?
nuclease and helicase
What is a joint molecule and when does it form?
when undamaged and damaged sister chromatids cross over; occurs during homologous recombination
