Biology 1002B Lecture Notes - Fall 2018 Lecture 18 - Biochemical cascade, Homeobox, Eukaryote
Document Summary
Missense mutation: mutated base pair (snp) leads to altered sense codon leads to altered amino acid. Silent mutation: it"s perfectly possible to su er a mutated base pair (snp) that would have no e ect on which amino acid is coded for. Nonsense mutation: mutated base pair (snp) from normal, codon changed to stop, premature termination of polypeptide. Frameshift mutation: insertion or deletion of a single base pair can have devastating e ects because it shifts the reading frame of a gene (codons come in groups of 3, everything downstream of an in/del mutation is wrong) *in/del is therefore more troublesome than a snp. Consider a single base pair insertion into the dna coding for the rst exon of an mrna sequence. The resulting protein is likely to be too short if the insertion results in a premature stop codon. The resulting protein is likely to be too long if the insertion causes a frameshift and collapses the stop codon.