Practice: Kinases and phosphatases are essential to the cell because they:
a) Are enzymes that synthesize proteins.
b) Are enzymes that degrade proteins.
c) Are enzymes that can turn proteins “on” and/or “off” through changes in phosphorylation.
d) Are enzymes that can turn proteins “on” and/or “off” through changes in proton concentrations.
e) None of the above.