An enzyme's reaction rate falls when surrounding temperature drops far below its optimum, yet warming restores the original rate. Which account explains the slowdown?

Core Concept

Temperature controls how fast molecules move. In the cold, substrates travel more slowly and strike active sites less frequently each second, so fewer enzyme-substrate complexes form and the observed rate sinks. Because moderate chilling leaves the folded protein undamaged, restoring warmth revives molecular motion and the original velocity returns. This reversible kinetic slowdown contrasts sharply with denaturation, which destroys structure and cannot simply be warmed away.