Lac operon slideshare
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What happens to the lac operon when both glucose and lactose are present...
The relationship between external glucose concentration and cAMP levels inside Escherichia coli: implications for models of phosphotransferase-mediated regulation of adenylate cyclase
The concentration of glucose in the medium influences the regulation of cAMP levels in Escherichia coli.
Trp operon
Growth in minimal medium with micromolar glucose results in 8- to 10-fold higher intracellular cAMP concentrations than observed during growth with excess glucose. Current models would suggest that the difference in cAMP levels between glucose-rich and glucose-limited states is due to altered transport flux through the phosphoenolpyruvate: glucose phosphotransferase system (PTS), which in turn controls adenylate cyclase.
A consequence of this model is that cAMP levels should be inversely related to the saturation of the PTS transporter. To test this hypothesis, the relationship between external glucose concentration and cAMP levels inside E.
coli were investigated in detail, both through direct cAMP assay and indirectly through measurement of expression of cAMP-regulated genes. Responses were