Test 3- Mutations and Mendelian Genetics Flashcards
(28 cards)
point mutations
bp substitution missense mutation nonsense mutation neutral mutation frameshift forward reverse suppressor
bp substitutions
transition
transverion
transition
AT-GC
transversion
AT-TA
missense mutation
different aa inserted
nonsense mutation
premature stop codon
neutral mutation
no change in protein function
silent mutation
no change in aa
frameshift mutation
changes reading frame w/ addition or deletion
forward mutation
wt to mutant
reverse mutation
mutant to wt
true: back to wt aa
partial: change that restores partial function
suppressor mutation
mutation at another site that diminish or abolish affect of original mutation
intragenic: same gene
intergenic: different gene
- tRNA nonsense suppressor
spontaneous mutations
replication errors
- tautomeric shift
- insertion/deltion
- chemical changes (depurination/deamination)
tautomeric shifts
AC and TG base pairing
insertion/deletion
looping occurs in regions with repeated bp sequence
depurination
A or G bond to sugar breaks losing base
deamination
removes amino group from base
C to U, 5mC to T
induced mutation
ionizing -xrays UV light chemical mutagens -base analogs -base modifiers -intercalating agent
xrays
break sugar phosphate backbone
UV
forms thymine dimers
Base analogs
5 bromo-uracil (like T)
bp in enol state with G (TA to CG)
base modifiers
nitrous acid -deaminates GCA (G no effect) -causes transition mutations -can revert hydroxylamine -hydoxylates C to pair with A -cant revert alkylating agents -MMS/EMS -GC to AT
intercalating agents
proflavin, acridine, ethidium bromide
cause bp insertions/deletions by inserting into helix
ames test
tests for mutagens
his auxotrophs plated with liver enzymes and potential mutagen to look for revertants as seen by inc. growth
