A Catalyst is any substance that works to accelerate a chemical reaction. Catalysts can be organic, synthetic or metal. The process by which the catalyst speeds up or slows a reaction is called catalysis.

For any process to occur, energy, known as activation energy is required . Without the help of a catalyst the amount of energy needed to spark a particular reaction is high. When the catalyst is present the activation energy is lowered making the reaction happen more efficiently. The catalyst generally works by either changing the structure of a molecule or by bonding to reactant molecules causing them to combine, react and release a product or energy. For example, a catalyst is required for oxygen and hydrogen gases to combine and form water.

Without the help of a catalyst, chemical reactions might never occur or take a significantly longer period of time to react. When the chemical reaction occurs, the catalyst itself is not changed and is not part of the end result. Most times the catalyst can be reused over and over in subsequent reactions.

Sometimes instead of accelerating a reaction, a catalyst works to slow a reaction that would normally not occur or occur very slowly. This type of substance is a negative catalyst which is also referred to as an inhibitor. Negative catalysts are important in medicine where inhibitors are critical in treating mental illnesses, high blood pressure, cancer and a myriad of other health problems.

A catalyst is used in two types of conditions, either chemical or biochemical. The most common catalyst in biochemical reactions are enzymes. Enzymes are highly specialized proteins which accelerate specific chemical reactions. These catalysts make life possible. For example an enzyme found in saliva breaks up food for digestion on contact. With out this catalyst it would take weeks for us to digest our food.

Catalysts are also important in the laboratory as well as in manufacturing and industry. One of the most famous catalysts is the catalytic converter which helps to prevent automobile emissions and make fuel consumption more efficient. Fertilizers are also catalysts which speed up plant growth.