Biology 1001A Chapter Notes -Inverted Repeat, Insertion Sequence, Chromosome
11 Feb 2014
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Most of mistakes made by dna pol are base-pair mismatches. 12. 4a proofreading depends on the ability of dna pols to revers and remove mismatched bases. Proofreading mechanisms depend on ability of dna pol to back up and remove mispaired nucleotides. If there is a mismatch, dna pol backs up. Dna pol can only add complimentary base pairs when most recent bases are paired correctly. 12. 4b dna repair corrects errors that escapes proofreading. Mismatch repair mechanisms fix base pair mismatches that remain after proofreading. Repair enzymes move along double-helix, looking for distortion (damage) They remove several bases (before and after the mismatch) If errors still remain after dna repair they can become mutations. Move from place to place within a genome. 9. 4a insertion sequence elements and transposons are the two major types of prokaryotic mobile elements. Transposable elements (tes): their mechanism of movement is called transposition. They are never jumping because they make contact between initial and final sites.
