Question

How to draw a regulatory graph of enzyme glycogen phosphorylase with high ATP and low glucose, with axes labeled, 3 plots on the graph and labeled with given regulators and no regulator present, and plots the correct shape

Answer 1

High ATP acts as allosteric inhibiters of enzymatic activity and called as negative heterotrophic effectors

The binding of these negative effectors to the allosteric site, reduces the affinity of the phosphate ion to the enzyme glycogen phosphorylase as seen in the green colour plot with the increase in the Km value ( Km1)

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When glucose level is low, the AMP level increases, these AMP molecules acts as

Positive regulators and called as positive heterotropic effector.

Their binding to the allosteric site enhances the affinity of the enzyme glycogen phosphorylase to the phosphate ion which can been seen in the black colour plot with decrease in the Km value ( Km2)

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When there is no regulator present, the plot of enzyme activity lies within the plots of positive and negative regulation as shown with colour red. The Km value also lies intermediate between the Km1 and Km2