How do enzymes accelerate biochemical reactions?

Enzymes are biological catalysts that increase the rate of biochemical reactions primarily by lowering the activation energy required for the reaction to proceed. Activation energy is the minimum energy needed for a reaction to occur, and by lowering this barrier, enzymes make it easier for the reactants to convert into products.

Enzymes achieve this by stabilizing the transition state of the reaction, providing an alternative pathway that requires less energy. This allows more substrate molecules to have enough energy to reach the transition state under the same conditions, thus increasing the reaction rate. Importantly, enzymes are not consumed in the reaction and can be reused multiple times.

In contrast, increasing the temperature can enhance reaction rates, but it's not the specific mechanism by which enzymes function. Using energy from ATP is a feature of certain cellular processes but not a general mechanism for enzyme action. Altering the substrate structure doesn't accurately describe the role of enzymes, as they typically bind to substrates in their original form and facilitate the transition to products without changing the substrates themselves. Therefore, the correct understanding of how enzymes work centers on their ability to lower activation energy.