MBIO 4600 Lecture Notes - Lecture 15: Deamination, Irradiation, Base Pair
25 Dec 2015
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Document Summary
Dna damage (i. e. lesion) can: be deleterious (i. e. prevent replication so cells die, increase the frequency of mutations (i. e. mutagenic) Mutagenesis vs. dna damage: mutations are permanent, heritable changes in the nucleotide sequence of dna, chemical damage to dna is not by itself a mutation, but can result in a mutation if the cell survives. Either damage is not repaired or errors occurred during. Survival of cells with continuous vs. intermittent chemical treatment: repair occurs during the rest periods increasing cell survival rate (cid:1) Single base pair change = base substitution. Silent mutation = base substitution no change in amino acid. Missense mutation = base substitution change in amino acid sequence sequence. Neutral mutation no detectable effect on protein function. Nonsense mutation conversion of normal to nonsense (i. e. stop) codon (uaa, uag, uga) causing premature termination of translation. Addition or deletion of nucleotide(s) altered reading frame affecting polypeptide sequence. Hydrogen atom and single bond switch with adjacent double bond.
