Kinetics and Enzymes

Kinetics governs how quickly a chemical reaction occurs. Chemical reactions may be exergonic or endergonic. During an exergonic reaction, molecules with high free energy, become molecules with low free energy. These reactions generally release energy and thus have a negative delta G value, are favorable and spontaneous. Endergonic reactions do the opposite, turning molecules with low free energy into molecules with a high free energy. Therefore, exergonic reactions require energy, which is stored within the bonds of the molecules. This also means the reaction has a positive delta G, is unfavorable and not spontaneous.

In order to make a chemical reaction occur more quickly, enzymes are used. The mechanism by which enzymes work is described by an induced fit concept. This means that the enzyme orientates molecules in such a way to favor the transition state of a reaction. In other words, the delta G of the transition state is decreased, decreasing the activation energy of the reaction. It is important to note that the delta G of the reaction of as a whole, the difference between products and reactants, does not change.