Question

an enzyme is considered ______ because it speeds up chemical reactions without being used up. a substrate a catalyst a cofactor a complex denatured

Explanation:

Enzymes are biological catalysts. They increase the rate of chemical reactions and remain unchanged at the end of the reaction, just like general - catalysts in chemistry. A substrate is the molecule on which an enzyme acts, a co - factor is a non - protein molecule or ion that helps an enzyme in its activity, a complex is a combination of molecules, and denatured refers to an enzyme losing its structure and function.

Answer:

B. a catalyst