Question

Bacteria that use the lac operon are grown in a laboratory under conditions of high lactose and no glucose. A researcher then adds progressively more and more glucose to the bacteria. Which of the following describes the temporal changes the bacteria experience in this experiment? Bacteria that use the lac operon are grown in a laboratory under conditions of high lactose and no glucose. A researcher then adds progressively more and more glucose to the bacteria. Which of the following describes the temporal changes the bacteria experience in this experiment? cAMP levels will fall and expression of the lac operon will decrease as a function of time in the experiment. cAMP levels will rise and expression of the lac operon will decrease as a function of time in the experiment. cAMP levels will remain constant and expression of the lac operon will increase as a function of time in the experiment. cAMP levels will rise and expression of the lac operon will increase as a function of time in the experiment.

Answer 1

The correct answer is cAMP levels will fall and the expression of lac operon will decrease as a function of time in the experiment.

Step-by-step explanation:

cAMP or cyclic AMP is a positive regulator of lac operon that means cyclic AMP helps to increase to the expression of the structural genes of lac operon.

On the other hand glucose is a negative regulator of lac operon.Glucose generally represses the activity of adenylyl cyclase enzyme that helps in the formation of cAMP from ATP.

The repression in the activity of adenylyl cyclase lowers the cellular level of cAMP.As a result the expression of lac operon decreases.