Enzymes lower the activation energy necessary to transform a reactant into a product. On the left is a reaction that is not catalyzed by an enzyme (red), and on the right is one that is (green).

The activation energy barrier separates reactants from products. The top of the barrier is the transition state. Putting the right amount of energy into the reaction allows the reactants to surmount ...

The binding of the enzyme to its substrate also lowers the activation energy of the reaction (amount of energy needed to make a reaction happen). If an enzyme is present, the amount of energy ...