So enzymes are these proteins found inside our body that bind to specific substrate molecules and accelerate the reaction, basically increase the rate at which that reaction actually takes place. Enzymes are biological catalysts, and we have many different types of enzymes in our body. For example, just in our immune system alone, we have many, many, many proteins. These protective proteins we call antibodies. And our body manufactures these antibodies so that they bind to specific types of molecules we call antigens. So for every antigen, we have a specific type of antibody that can bind to that antigen and that antigen alone.