Biology 1201A Lecture Notes - Lecture 2: Reading Frame, Deoxyribose, Pyrimidine
18 Dec 2017
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Topic 3: generating diversity origins of variation, new alleles. Mutations: double stranded, heritable changes in the dna sequence. If there is a single stranded change it is not a mutation, it is just dna damage. ". Example: snp single nucleotide polymorphism: tautomeric shifts: spontaneous shift between constitutional isomers of bases, resulting in alternative h-bond patterns. Different isomers of a, t, c, and g can cause a mis-pairing of the base pairs. New base pairs of these isomers are g&t and c&a. Causes a single strand change dna damage then after dna replication a mutation is formed: deamination: removal of an amine group from a base, resulting in altered h- bond patterns. Also know as deletion: depurination: disruption of bond between purine and deoxyribose, resulting in an apurinic site. After dna replication the unpaired nucleotide either gets skipped, or.
