An enzyme has finished catalyzing its reaction. What state is the enzyme itself in?

1. Enzymes can lower activation energies by taking part in the chemical reaction itself, even forming covalent bonds with substrate molecules. 2. Even so, the enzyme will always return to its original state at the completion of the reaction. 3. One of the hallmark properties of enzymes is that they remain ultimately unchanged by the reactions they catalyze. 4. After catalysis the enzyme releases its products rather than holding on to them. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 6 "Metabolism", section 6.5 Enzymes_