What happens to an enzyme after a biochemical reaction?

Nothing--enzymes make reactions go faster (catalyze reactions), but once the reaction is complete the enzyme is just like it was before the reaction.

Therefore, the rate of most biochemical reactions must be increased by a catalyst. A catalyst is a chemical that speeds up chemical reactions. In organisms, catalysts are called enzymes. Like other catalysts, enzymes are not reactants in the reactions they control. Dec 5, 2014