MIC 102 Lecture Notes - Lecture 11: Transposase, Point Mutation, Missense Mutation
28 Oct 2017
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Document Summary
Mutation: any change in dna sequence inherited by offspring. Some mutation have no observable affect on phenotype. Auxotrophs lose the ability to synthesize building blocks or growth factors. Frameshift can affect the reading frame by 1 or 2 nucleotides. Duplications can lead to new functions over time. One mutation can be considered to fit multiple types: inversion might cause missense. Spontaneous mutations occur rarely: 1 in a million base pairs in polymerase, with proofreading down to 1 in a billion, spontaneous deamination converts c -> u, is then read as t and incorporates an. A across from it: physical agents: ionizing radiation, chemical agents. Enrichment: grow in medium without the component you want to find auxotrophs for. Mobile elements are pieces of dna that can move themselves around a chromosome. Each element has a transposase gene and terminal inverted repeats. Transposition can land a mobile element inside of an existing gene. Noncomposite transposons: also contain a drug resistance gene.
