In a chemical reaction, a reactant binds to an enzyme at a region known as the___.

A. Catalyst

B. Product

C. Substrate

D. Active site

I think the correct answer among the choices listed above is option D. In a chemical reaction, a reactant binds to an enzyme at a region known as the active site. Enzymes are used as a catalyst for a certain reaction in order to hasten the reaction.

enzymes are biological molecules that catalyse the chemical reactions in the body. Catalysts speed up the rate of the reaction

reactants of the chemical reaction binds to a specific region of the enzyme called the active site, while bound to the active site the reactants are transformed to the products and released from the active site of the enzyme.

the enzyme remains unchanged at the end of the reaction

the active site has a complementary shape to that of the of the shape of the substrate which binds to the active site

therefore answer is

In a chemical reaction, a reactant binds to an enzyme at a region known as the D. active site