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Ch. 16 vocabulary
Microbiology
Question | Answer |
---|---|
Active repressor complex | formed when tryptophan binds to the aporepressor--binds at the beginning of the trp operator and inhibits transcription |
Aporepressor | a separated gene from the operon produces an inactive repressor--protein is normally inactive |
Corepressor | tryptopan--causes repression |
Feedback inhibition | end product inhibits expression of its own pathway--many anabolic pathways directly regulate expression in this manner--ample product--system's expression repressed |
Gene expression | prokaryotes--gene expression control seen at level of transcription--2 major classes--inducible/repressible |
Inducible genes | normally turned off--unless energy source is available in environment |
Induction | (blank) |
lac operon | features that control expression--3 proteins encoded by lac operon--lacZ, lacY, lacA--efect lactose catabolism (degredation) |
Operator | (lacO) binding site of protein to a specific DNA |
Promoter | (lacP) |
Repressible systems | can be turned off at the transcriptional level when it is advantageous to the cell |
Repressor | protein that binds to a specific DNA sequence just upstream of the 3 cistrons of the lac operon |