01:119:115 Lecture Notes - Lecture 16: Lac Operon, Lactose Permease, Operon

• School: Rutgers University
• Department: Biological Science
• Course: 01:119:115
• Professor: Christy Beal

Document Summary

I. regulation of prokaryotic genes- intro: only a certain subset of genes are used at any given time, constitutive genes = (housekeeping genes) If every cell in your body has the same genome, why are all of your cells not identical: always need + constantly transcribed, e. g. enzymes involved in respiration. If you stop making constitutive genes you shall die: other genes are only transcribed when needed. 3 genes for lactose metabolism in e. coli: i. lac y- lactose permease- brings lactose into cell ii. lac z - beta-galactosidase (b-gal)- hydrolyze lactose glucose and galactose iii. lac a- galactoside transacetylase- aids in lactose metabolism. If no lactose- e. coli cell does not make these enzymes. Operon = a group of genes controlled by a single regulatory signal controlled by an operator. as one long mrna segment i. spliced into separate segments. ii. operons are one unit of transcription. iii. all together or not at all.