BIOL 4246 : Beginning Of Exam 3 Material 1st Lecture 11 1 16
Document Summary
Chemotaxis: often based on dna sites, up & down mutations based on consensus, promoters, lacia , lacuv5, activator/repressor sites lacoc, replication sites dna boxes, data sites, others: Rna or protein: mutation in orf. Frameshift insertion/deletion that is not a multiple of 3. Reverse mutation: restores the wild-type phenotype, a mutation to wt gene creates a mutant gene; reverse mutation reverts to original, two types, back mutation precise restoration of dna sequence, second-site (compensatory) mutation. A second change in dna sequence restores wt phenotype: example: suppressor trna suppress nonsense mutation & frameshift mutations. Nonsense mutation suppressed by second-site mutation in trna gene. Trna anticodon is altered to base pair with nonsense codon. Supe44 (common amber suppressor) or glnv glu trna. Not 100% ef cient because of the 2 possibilities. Make about 10-30% of normal amounts (enough to survive) Most bacterial orf end in more than one stop codon.
