Bio 93 Beginning of Lecture 23

What can affect protein structure and function?

mutations of one or a few nucleotides
What are mutations?

changes in the genetic material of a cell or virus
What are point mutations?

chemical changes in just one base pair of a gene
What are the two types of small-scale mutations?
- nucleotide-pair substitution
- one or more nucleotide-pair insertions or deletions
nucleotide-pair substitution

replaces one nucleotide and its partner with another pair of nucleotides
silent mutations

have no effect on the amino acid produced by a codon because of redundancy in the genetic code
missense mutations

still code for an amino acid, but not the correct amino acid
nonsense mutations

change an amino acid codon into a stop codon, nearly always leading to a nonfunctional protein
Insertions and deletions are:

additions or losses of nucleotide pairs in a gene
Insertions or deletions have a _______ effect on the resulting protein more often than substitutions do

disastrous
Insertion or deletions of nucleotides may alter the reading frame, producing a ______________

frameshift mutation
What are mutagens?

physical or chemical agents that can cause mutations

Author

jocelyn8

336645

Card Set

Bio 93 Beginning of Lecture 23

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final

Updated

2017-12-08T05:19:40Z