So enzymes themselves are not actually consumed during reactions, although they might alter in some way. For example, when the reaction binds to the active side of our enzyme, it might change its shape ever so slightly. But at the end of the reaction, our enzyme is always regenerated in the same form as it basically went in to our reaction. So this is a very important property of enzymes because that means a very small quantity of enzymes can be used to basically speed up many reactions at the same exact time. We do not have to actually use up our enzyme and create new enzymes because one enzyme can basically react with many different reactants. So that is expressed in the following expression.