10-25-11_DNArepair_transcriptionA

10-25-11_DNArepair_transcriptionA - DNA Error Detection and...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Can you do anything correctly one billion times in a row? DNA Error Detection and Repair
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Announcements CELLLS part 1 is due November 7, at 5 pm The next quiz will come out on Friday and will be due on Wednesday. It will cover DNA repair and transcription.
Background image of page 2
Types of damage experienced by DNA Ionizing radiation can break DNA backbone Exposure to a variety of reactive chemicals, some made by cell metabolism, can alter DNA bases structurally Ethyl methansulfonate (EMS) is a chemical mutagen that creates point mutations and is used as a research mutagen Ultraviolet radiation causes adjacent pyrimidines (C,T) to interact covalently, forming a dimer Absorption of thermal energy generated by metabolism in a warm- blooded bird or mammal can split adenine & guanine from their attachment to DNA backbone sugars Pyrimidine dimer
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Consequences of DNA damage If mutation occurs in a pre-gamete, genetic alteration may be passed on to next generation Somatic (cells not in germline) mutations can interfere with transcription and replication Can also lead to the malignant transformation of a cell Can also speed the process by which an organism ages Copyright 20th Century-Fox Film Corporation
Background image of page 4
NAME PHENOTYPE ENZYME OR PROCESS AFFECTED MSH2, 3, 6, MLH1, PMS2 colon cancer mismatch repair Xeroderma pigmentosum (XP) groups A–G skin cancer, cellular UV sensitivity, neurological abnormalities nucleotide excision-repair XP variant cellular UV sensitivity translesion synthesis by DNA polymerase δ Ataxia–telangiectasia (AT) leukemia, lymphoma, cellular γ-ray sensitivity, genome instability ATM protein, a protein kinase activated by double-strand breaks BRCA-2 breast and ovarian cancer repair by homologous recombination Werner syndrome premature aging, cancer at several sites, genome instability accessory 3′-exonuclease and DNA helicase Bloom syndrome cancer at several sites, stunted growth, genome instability accessory DNA helicase for replication Fanconi anemia groups A–G congenital abnormalities, leukemia, genome instability DNA interstrand cross-link repair 46 BR patient hypersensitivity to DNA-damaging agents, genome instability DNA ligase Alberts et al., Molecular Biology of the Cell Syndromes caused by DNA damage
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Three Steps That Give Rise to High-Fidelity DNA Synthesis REPLICATION STEP ERRORS PER NUCLEOTIDE
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 26

10-25-11_DNArepair_transcriptionA - DNA Error Detection and...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online