Specifically, we have to input this amount of energy, which is our activation energy, it's the activation barrier. So basically, if we input this amount of energy, the reactants can basically reach the transition state and then convert to the product. And what protein enzymes do, what enzymes do is they basically bind to the reactants in some form or way and they actually lower the activation energy by basically providing a completely different reaction pathway. So the rate of chemical reactions depends on its activation energy and enzymes increase the rates of reactions by decreasing the activation energy. The activation energy is the amount of energy that must be added to our system, to our reaction, to transform the reactants to the transition state and then to our products. So basically, this is the first important point that we must know about enzymes.