The Human Body: General Acid-Base Catalysis

In nature simple molecules will bind with other molecules to transform into macromolecules and in-turn these more complex molecules will degrade back into their simple form. The duration of these chemical reactions will vary and can take years to successfully change from one structure to another. Although, this process may work at times in the physical world, the human body does not have years to wait on reactions such as the transformation of food into usable energy. This is why the metabolic process within living beings will produce enzymes that will help catalyze chemical reactions. One particular catalytic mechanism that can enhance the rate of a reaction is known as general acid-base catalysis. This mechanism lowers the activation energy, transfers a proton as a donor or acceptor, and is one of the most common biochemical reactions in the human body.

During the binding process the substrate requires some assistance in order to bind to the enzyme properly. This is done by several different catalytic mechanism. The most abundant catalytic mechanism is known as the general acid-base catalysis. For this reaction to occur, one of the eight amino acid residues, shown in fig 6-9, will act as a proton donor or a proton acceptor. The amino acid residues known for their acidic form will function as the proton donor and the residues that form a base will act as a proton acceptor. The low bond dissociation energy formed by hydrogen bonding is what makes transferring of a proton more favorable within an enzyme. This allows the enzyme to achieve its characteristic features as a catalyst without undergoing any chemical reactions