What term describes a substance that speeds up a chemical reaction by providing an alternative pathway with lower activation energy?

• A. Catalysts
• B. Enzymes
• C. Inhibitors
• D. Reactants

Answer: (A)

The main idea is that a substance can increase a reaction’s rate by offering a different route that requires less energy to get over the barrier, known as activation energy. This is exactly what a catalyst does: it provides an alternative pathway with a lower activation energy, so more reactant molecules have enough energy to react in a given time. Because catalysts are not consumed in the reaction, they can continue to speed up the process without being used up. Enzymes are a natural example of catalysts in biology, acting on specific reactions to raise the rate. Inhibitors do the opposite by slowing or stopping reactions, and reactants are simply the starting substances that react. So the best term for this description is catalyst.