A) ATP inhibits and CTP activates
B) ATP activates and CTP inhibits
C) Both ATP and CTP inhibit
D) Both ATP and CTP activate
E) none of these is true

A) Feedback inhibition by product.
B) Addition or removal of phosphate groups from of the enzyme.
C) Presence of activators.
D) Activation of zymogens.
E) All of these regulate enzyme activity.

A) Binding of one substrate molecule prevents the enzyme from working at all.
B) Binding of one substrate molecule inhibits the binding of a second substrate.
C) Binding of one substrate molecule enhances the binding of a second substrate.
D) Binding of one substrate molecule inhibits the binding of other effectors.