Cells Regulate Their Level of Activity by Regulating the Amount

Cells regulate their level of activity by regulating the amount of proteins present in the cell at any given time,so an up regulation of enzymes would be expected to

A) increase the level of productivity of chemical reactions that rely on them.
B) decrease the level of productivity of chemical reactions that rely on them.
C) increase the rate of reactions catalyzed by the enzymes.
D) decrease the rate of reactions catalyzed by the enzymes.
E) both decrease the level of productivity of chemical reactions that rely on them and decrease the rate of reactions catalyzed by the enzymes.