Types of DNA damage — Flashcards

Flashcard 1: Chronic exposure to Arsenic may cause cancer by metabolites (ex. Dimethyl-Arsenic) inhibiting _____ motifs in Base-Excision Repair and Nucleotide-Excision Repair enzymes

Answer: zinc finger

Flashcard 2: Mechanisms to repair _____ breaks are defective in Ataxia telangiectasia, Fanconi anemia, and SCID

Answer: dsDNA

Flashcard 3: Non-ionizing radiation causes carcinogenesis by generating _____

Answer: pyrimidine dimers

Flashcard 4: What form of DNA repair fixes mutations induced by UV radiation?_____

Answer: nucleotide excision repair

Flashcard 5: What form of DNA repair fixes mutations due to spontaneous/toxic deamination?_____

Answer: Base excision repair

Flashcard 6: What mutation is induced by UV radiation?_____

Answer: Pyrimidine dimers (e.g. thymine dimers)

Flashcard 7: What process is used by mismatch repair enzymes to distinguish between old and new DNA strands in prokaryotes?_____

Answer: DNA methylation

Flashcard 8: What are the four mechanisms of DNA repair?

Answer: Nuceotide excision repair Base excision repair Mismatch repair Nonhomologous end joining

Flashcard 9: non-homologous end joining

Answer: join 2 dsDNA ends

Extra: double-stranded breaks (when no homologous chromosome is around to use as a guide)ataxia telangiectasia

Flashcard 10: mismatch repair

Answer: 1. new strand recognized (lacks methylation) 2. mismatched nucleotides removed 3. DNA pol/ligase fills/seals gap

Extra: Mismatched bases on newly synthesized DNA strandhereditary nonpolyposis colorectal cancer (HNPCC)