Which term describes a substance that speeds up a chemical reaction without being consumed?

• A. Catalyst
• B. Enzyme
• C. Substrate
• D. Product

Answer: (A)

A catalyst speeds up a chemical reaction without being consumed because it provides an alternative reaction pathway with lower activation energy, so more particles have enough energy to react. It’s not used up in the process and can continue to work again and again. That general term is exactly what the option describes. An enzyme is a specific type of catalyst found in living organisms, so it shares the same idea but is more specialized. The substrate is the molecule that reacts, and the product is what’s formed—neither is the agent that speeds the reaction.