Induced Mutations from DNA Damage by Chemicals + Radiation Flashcards
e.g of mutagen that’s a natural component of environment
fungal toxins
cosmic rays
UV light
e.g of unnatural/human made mutagens
industrial pollutants, medical X-rays, chemicals in tobacco smoke
what are compounds called that can substitute for purines/ pyrimidines
base analogs
what’s first chemical mutagens identified in chemical warfare
sulfur-containing mustard gas
what do mustard gases do in nucleotides
donate alkyl group to amino/keto groups
what are intercalating agents
chemicals that have dimension + shapes so wedge between DNA base pairs
what do wedged intercalating agents do
cause base pairs to distort and DNA to unwind
what good thing are some intercalating agents used for
cancer treatments (chemotherapy)
what’s a group of chemicals that cause mutations
adduct-forming agents
what’s the mutagenic component of cigarette smoke
acetaldehyde
when are heterocyclic amines (HCAs) causing cancer produced
when cooking some meats
what wavelengths can disrupt organic molecules (UV light)
waves of shorter length than visible light
what do purines and pyrimidines do when it comes to UV light
absorb it
how many DNA lesions can UV induce in an hour
1000s
what’s a major effect of UV radiation that distorts DNA and stops normal replication, introducing errors
pyrimidine dimers
3 rays that are more energetic than UV and penetrate deeply into tissues
X rays
Gamma rays
Cosmic rays
what do X rays, Gamma rays and Cosmic rays cause
ionisation of molecules
what does ionisation of molecules turn stable molecules + atoms into
free radicals
e.g of what free radicals can do
alter pruines + pyramidines
break phosphodiester bonds
produce chromosomal aberrations (deletions, translocations, fragmentation)
how much of human radiation exposure is from human-made sources
less than 20%
where does more than half human-made radiation exposure come from
medical x-rays
radioactive pharmaceuticals
