Are enzymes protein catalysts?

The correct answer to this question is yes, enzymes are protein catalysts. In fact, the central role of enzymes - which are proteins or RNA - is to act as catalysts in biological reactions to increase the rate and speed of chemical reactions. Chemical reactions would take years if not for catalysts. Typically, the chemical reactions brought on by enzymes take place within the cells.

Enzymes, like all other catalysts, have two characteristics. One, they increase the rate of chemical reactions with other substances without changing themselves. Two, enzymes increase reaction rates without changing the chemical relationship between reactants and products.