13. Mutations Flashcards
•any permanent heritable change in the DNA base sequence of an organism
mutations
purine-purine or pyrimidine -pyrimidine mutation
transition
point mutation
enumerate
- transition
- transversion
- silent mutatin
- missense mutation
- nonsense mutaion
purine-pyrimidine or pyrimidine -purine mutation
transversion
- new codon codes for the same amino acid
* no effect on protein
silent mutation
new codon codes for diff amino acid
missense mutation
new codon is a stop codon
shorter than normal, usually non fx protein
nonsense mutation
deletion or addition of bases
frame shift mutation
- loss of large areas of chromosomes durign unequal crossover in meiosis
- loss of fx
- protein shorter than normal or entirely missing
large segment deletion
ex. Tay-Sachs
Splice donor/acceptor
ex. Gaucher
Splice donor/acceptor
ex. ß-thalassemia
Splice donor/acceptor
- splice site is lost
* variable effects –> addition or deletion of a few amino acids to deletionof an entire exon
Splice donor/acceptor
- expansions in coding regions cause protein product to be longer than normal and unstable
- diseases often show anticipation in pedigree
triple repeat expansion
ex. huntington disease
triple repeat expansion