Lactase functions as a catalyst in the digestion of lactose. It is:

Lactase functions as a catalyst in the digestion of lactose. It is:

• A. Substrate
• B. Inhibitor
• C. Coenzyme
• D. Catalyst

Answer: (D)

Enzymes act as biological catalysts, speeding up chemical reactions by lowering the activation energy and remaining unchanged after the reaction. Lactase is an enzyme that catalyzes the breakdown of lactose into glucose and galactose. In this role, the molecule lactose is the substrate, while lactase itself is the catalyst. It is not an inhibitor, which would slow or stop a reaction, nor a coenzyme, which are non-protein helpers that assist enzymes. Because the enzyme is not consumed, lactase can catalyze many lactose molecules repeatedly.

Enzymes act as biological catalysts, speeding up chemical reactions by lowering the activation energy and remaining unchanged after the reaction. Lactase is an enzyme that catalyzes the breakdown of lactose into glucose and galactose. In this role, the molecule lactose is the substrate, while lactase itself is the catalyst. It is not an inhibitor, which would slow or stop a reaction, nor a coenzyme, which are non-protein helpers that assist enzymes. Because the enzyme is not consumed, lactase can catalyze many lactose molecules repeatedly.