So let's suppose we have reactants A and B. We place our enzyme, that enzyme basically takes A and B and reacts them. It decreases the activation energy to form product C and D. But the actual enzyme on the product side is exactly the same as the enzyme on the reactant side. They are not actually used up or destroyed in any way or form. So these are the four important points that you must always remember about the role of enzymes in the human body. So enzymes affect kinetics.