mutagenesis and dna repair Flashcards
-any change in the genetic code
-changes caused by errors in dna replication or errors in dna repair
-raw materials of evolution
mutations
mutations are considered a ___-___ ___.
double-edged sword
point mutations:
-silent
-substitution
frameshift mutations:
-insertion
-deletion
individuals with greater risk of malignancies compared to caucasians and asians
african descent
individuals with greater risk of BRCA gene mutation
Ashkenazic Jews and Icelanders
short term consequences of dna damage
-physiological dysfunction
-cell death
-abnormal growth and metabolism
long term consequences of dna damage
-aging
-cancer
-disease
-activated by dna damage
-prevents dna replication
-activates proteins to repair dna
p53 protein
when wrong nucleotides are paired
mismatch
processes mispairs that result from heteroduplex DNA formed during generic recombination
Mismatch Repair (MMR)
4 phases of MMR
-recognition of a mismatch by MutS proteins
-recruitment of repair enzymes
-excision of the incorrect sequence
-resynthesis by DNA polymerase using the parental strand as a template.
short patch of DNA excised, repaired by reploymerizationand ligation
nucleotide excision repair
2 routes for damage repair
-transcription-coupled repair
-global genomic repair
-UV sensitivity
-bird-like faces, tooth decay, and cataracts
-short stature
cockayne syndrome
