lecture 28 Flashcards
mutations
what are the TWO types of substitution mutations?
transition and transversion
what are exchanged in a transition mutation?
a purine for a purine or a pyrimidine for a pyrimidine
what are exchanged in a transversion mutation?
a purine for a pyrimidine
do transitions or tranversions occur more commonly? why?
transitions b/c they have similar shapes so they bind more easily
what are the THREE types of insertions/deletion mutations?
silent mutations, missense mutations, nonsense mutations
what type of mutation involves the changing of one codon to a synonymous codon and causes no change in the amino acid sequence of the protein?
silent mutation
what type of mutation is being referred to when “degeneracy of the genetic code” is mentioned?
silent mutation
what type of mutation involves the changing of one codon to a different codon and results in a change of the amino acid sequence of the protein?
missense mutation
what type of mutation involves the changing of one codon to a STOP codon and results in premature stoppage of translation?
nonsense mutation
what type of mutation involves the gain or loss of a nucleotide(s) that results in a change in the reading frame of the codon?
frameshift mutation
what type of mutation involves the gain or loss of a nucleotide or trinucleotide set and does NOT change the reading frame of the codon?
in-frame mutation
what does amorphic mean?
complete loss of gene function
do loss-of-function mutations generally produce phenotypes that are dominant or recessive?
recessive
what type of mutation results in a gene that has a gained a new and abnormal function?
gain-of-function mutation
what does neomorphic mean?
a new or different function from normal
do gain-of-function mutations generally produce phenotypes that are dominant or recessive?
dominant
what are somatic cells?
non sex cells
what are germ cells?
sex cells (gametes)
in what type of cells does a mutation cause a more severe manifestation and passes it does to future generations?
germ cells/gametes/sex cells
what type of mutation has no external regulator or artificial factor causing it?
spontaneous mutation
what type of mutation is a replication error?
spontaneous mutation
what allows non-complimentary bases to pair in a process known as “wobble”?
flexibility of DNA double helix
what type of replication error involves denaturation and displacement of DNA strands that results in a mispairing of bases?
slipped strand mispairing
what type of mutation is caused by normal chemical interactions that take place within the cell?
chemical changes
what type of chemical reaction involves a beta N-glycosidic bond being cleaved by hydrolysis that results in the release of an adenine or guanine from the DNA strand?
depurination
what type of chemical reaction involves the hyrdrolytic removal of an amine group from a nucleotide releasing ammonia and converting the nucleotide to another molecule?
deamination
the conversion of cytosine to uracil, releasing ammonia, is an example of what?
deamination
what is the most common single nucleotide mutation in DNA?
5-methycytosine to thymine deamination process
