27 - HIPFNER 1 Flashcards
what is the function of the sigma factor subunit of RNA polymerase
what is the organization of prokaryotic genes
many prokaryotic metabolic genes involved in the same process are organised into operons
what do activators and repressors do
how do effectors work
what are the components of the lac operon and what do they do
lac I: repressor protein
lacZ: beta galactosidase, which breaks down lactose into galactose and glucose, the latter of which bacteria are after
lacY is the permease protein, which lets lactose into the bacteria
what happens in the operon when there is no lactose present
what happens in the operon when lactose is present
how was the lac operon genetically analysed
what are the three main classes of lac mutants?
- structural (affect just one enzyme, the other is inducible)
- uninducible: can’t make LacZ and LacY in presence of an inducer, cannot be activated
- constitutive mutants: make both LacZ and LacY, even in the absence of an inducer, failure of repression
how did J+M test dominance and recessiveness
how do lac operon P mutations work
how do lac operon O mutations work
in what ways do promoters and operators act
act in a cis manner
