Enzymes

Enzymes are biological catalysts that speed up the rate of a chemical reaction. Being a catalyst, enzymes are not consumed during the reaction and are able to be used numerous times. Enzymes work by lowering the activation energy for a reaction, dramatically accelerating the rate of the reaction. Enzymes are composed of proteins, their exact function is determined by their structure, which is a combination of the sequence of amino acids (from which all proteins are composed). They assist in fighting aging, weight loss, lowering cholesterol, breaking down fats, improving mental capacity as well as the immune system and, building muscle from protein.

Each specific enzyme binds to a specific reactant or substrate, at an active site to begin the chemical reaction. Enzymes bond to the substrate much like a lock and key. The combining of the enzyme and substrate results in a slight change in the shape of both. This precise fit is called an induced fit; it acts to break old chemical bonds and form new ones, resulting in the formation of the product from the substrate.

Factors that affect enzymes, include temperature and PH balance. If the body is too hot then the enzyme's shape will be dramatically altered, causing difficulty in binding to the substrate. When the enzyme denatures or is altered due to these factors, its three-dimensional shape is lost (instead of being coiled, becomes uncoiled), causing the active site to no longer be a match for the substrate. If the pH were to change, it would cause the hydrogen bonds to break. Hydrogen bonds role is to stabilize the secondary structure, by placing hydrogen bridges at regular intervals. The loss of these bridges would cause the structure of the enzyme to change.

Most enzymes are aided by cofactors, nonprotein helpers for catalytic activity. They may be inorganic, such as metals (i.e. zinc, iron) or organic. If they are organic then they are referred to as coenzymes. Allosteric enzymes change shape between active and inactive stages, allosteric inhibitors induces the inactive form and allosteric activators induce the active form.

Inhibitors inhibit the action of enzymes. There are two types of inhibitors, competitive and noncompetitive. Competitive inhibitors take the place of the substrate, preventing the substrate from bonding to the enzyme. Noncompetitive inhibitors bind to the enzyme at a point away from the active site. It causes the enzyme to change shape preventing