BIOLOGY 172 Lecture Notes - Lecture 19: Permease, Wild Type, Disaccharide
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Gene expression control are all the controls at all the steps in the central dogma: transcription is normally the primary step of gene regulation. Constitutive expression: some genes are transcribed and expressed all the time (ex: rna pol for atp production) Galactose glucose glycolysis atp: coli only makes b-galactosidase in the presence of lactose very efficient because it does not have to make the enzyme unless it needs it. B-galactosidase expression is under inducible control; e. coli can be induced to produce b. galactosidase: lactose is the inducer (lactose increase; b-galactosidase increases) How does e. coli turn gene on and off: e. coli can detect levels of lactose and of change its gene expression in response to that. How do you find the gene that are involved in lactose production that b-galactosidase controls: mutagenic screen, take a bunch of normal e. coli cells and add a mutagen, which will overwhelm.