The role of glucose in catabolite repression is:()
A. Improving the activity of adenylate cyclase, to increase the concentration of intracellular cAMP.
B. Inhibiting the activity of adenylate cyclase, to decrease the concentration of intracellular cAMP.
C. Improving the activity of phosphodiesterase, to increase the concentration of intracellular cAMP.
D. Inhibiting the activity of phosphodiesterase, to decrease the concentration of intracellular cAMP.
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Which of the following conditions lead to the lowest expression of lac operon:()
A. Both glucose and lactose exist
B. Only glucose exists
C. Neither glucose nor galactose exists
D. Only lactose exists
Bacteria is intended to consume glucose at first, and enzymes to metabolize other sugars would be produced after exhaustion of glucose. This phenomenon can be called:()
Attenuation
B. Repression
C. Induction
D. Coordinate regulation
E. Catabolite repression
The repressor protein can binds to ___ and inhibit the transcription of structural genes.()
A. lac O
B. lac P
CAP binding site
D. lac I
In lac operon, ___binds to the repressor protein could initiate the transcription of structural genes.()
A. cAMP
B. Lactose
C. allolactose
D. CAP
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