DNA Repair

Question 1

Base Excision Repair: any stage

Answer 1

single base damage
oxidizing, methylating, alkylating, IR, xray
DNA glycosylase

Colorectal carcinomas

Question 2

Nucleotide excision repair: G1

Answer 2

segment of DNA damaged, pyrimidine dimers
UVC, cisplatin
Uvr/CP proteins

photosensitivity, skin cancer risk

Question 3

Mismatch repair: G2 (replication mistake)

Answer 3

mispaired nucleotides, insertions, deletions
slippage of polymerase
Mut and MMR proteins

hereditary non-polyposis colorectal cancer or lynch syndrome (AR)

Question 4

non-homologous end joining: G1 (no template, error prone)

Answer 4

double strand break (bad, missing DNA)
IR, chemicals
ligase

Fanconi anemia

Question 5

homologous recombination: G2 and S (template)

Answer 5

double strand break
IR, chemicals
copy and paste repair from template

Fanconi anemia