Enzymes lower activation energy

Enzymes are an important class of proteins that help in cellular processes. Enzymes are particular in their binding and can be allosterically regulated. In enzyme-catalyzed reactions, the enzymes lower the activation energy needed for a certain chemical reaction. The free energy of the reactants and products do not change, just the threshold energy level needed for the reaction to commence. Enzymes can lower the activation energy of a chemical reaction in three ways. One of the ways the activation energy is lowered is having the enzyme bind two of the substrate molecules and orient them in a precise manner to encourage a reaction. This can be thought of as lining the binding pockets up for the substrates so that it is not left to random chance that they will collide and be oriented in this way. Another way enzymes can lower the activation energy by rearranging the electrons in the substrate so that there are areas that carry partial positive and partial negative charges which favor a reaction to occur. Lastly, the enzyme can strain the bound substrate which forces it to a transition state that favors a reaction. By manipulating the substrates of the reaction, the enzyme can lower the necessary energy needed to make the reaction occur. The enzyme itself is not a component of the chemical reaction and is the same molecule at the beginning of the reaction as it is at the end.