Question

Fill out and explain. The boxes are supposed to hae a yes or no answer.

11. Fill in the following chart for a wild type e. coli Regulated events galactosidase Cell Conditions CAMP levels CAP bound to repressor bound? transcription at highest level? high? CAP site? high glucose low lactose low glucose T high lactose high glucose high lactose low glucose low lactose

Answer 1

	Regulated events
Cell condition	Repressor bound	cAMP level high	CAP bound to the CAP site	Galactosidase transcription at highest level
High glucose Low lactose	yes	low	yes	low
Low glucose High lactose	no	high	no	high
High glucose High lactose	no	low	no	low
Low glucose Low lactose	yes	high	yes	low

The cAMP level depends on the level of glucose in the cell, as the level of glucose is high in the cell the cAMP level is low while the glucose is low in the cell the cAMP level is high. In E. coli cell contains a protein called CRP. CRP-cAMP complex must be bound to a specific base sequences in the promoter region in order for transcription of the lac operon to occur. The cAMP-CRP complex is appositive regulator, in contrast to the repressor, a negative regulator.