Genetics Flashcards
(38 cards)
Errors in translation effect how many proteins?
1
Errors in transcription affect how many proteins?
affect a subset of proteins translated from the transcript with error
Mutations affect how many proteins?
ALL proteins encoded by that gene and ALL descendants of that mutant strain
Where do mutations arise?
During replication
What is the primary replicating polymerase?
DNA poly III
what are mutagens?
environmental factors that damage DNA
Benzopyrene mutagen, what does it do
dsDNA intercalating agents disort double helix
methyl-nitrosoguanidine mutagen, what does it do
chemical modification of base
UV light mutagen, what does it do?
base crosslinking
ionizing radiation mutagen, what does it do
base elimination
is a mutation heritable?
Yes.
What is a genotype
DNA sequence of a gene/chromosome
What is a phenotype
measurable/observable trait conferred by a gene, mediated by proteins
What is an allele
a version of gene
a random mutation will almost always result in protein what?
loss of function
very very rarely a what will arise that increases or changes protein activity
gain-of-function
Missense mutation
single base pair change that changes the codon to a different amino acid
nonsense mutation
single base pair that changes the codon to a premature stop codon
silent mutation
changes the codon but codes for the same amino acid due to degeneracy
frameshift mutation
insertion or deletion of base paris in amounts not divisible by 3. completley alter subsequent amino acid sequence
Polarity
side effect of mutations within operons
Order of how frequent
- mutagen
- slipped strand mispairing
- missense loss of function
- missense gain of function
How does DNA pol III repair a mismatch
exonnuclease activity, backs up one base and excises it
methyl - directed mismatch repair
repairs mismatch pairs
