AP BIOLOGY

Detailed explanation-1: -Enzymes (and other catalysts) act by reducing the activation energy, thereby increasing the rate of reaction. The increased rate is the same in both the forward and reverse directions, since both must pass through the same transition state.

Detailed explanation-2: -Enzymes generally lower activation energy by reducing the energy needed for reactants to come together and react. For example: Enzymes bring reactants together so they don’t have to expend energy moving about until they collide at random.

Detailed explanation-3: -Enzymes are biological catalysts. Catalysts lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy.

Detailed explanation-4: -The uncatalyzed reaction proceeds via a one-step mechanism (one transition state observed), whereas the catalyzed reaction follows a two-step mechanism (two transition states observed) with a notably lesser activation energy.

Detailed explanation-5: -If there is insufficient enzyme present, the reaction will not proceed as fast as it otherwise would because all of the active sites are occupied with the reaction. Additional active sites could speed up the reaction. As the amount of enzyme is increased, the rate of reaction increases.