A catalyst is any substance that works to accelerate a chemical reaction. It can be organic, synthetic or metal. The process by which this substance 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 one is present, the activation energy is lowered, making the reaction happen more efficiently. The substance 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, it 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. Inhibitors are important in medicine, where they are critical in treating mental illnesses, high blood pressure, cancer, and myriad other health problems.
A catalyst is used in two types of conditions, either chemical or biochemical. The most common in biochemical reactions are enzymes. Enzymes are highly specialized proteins that accelerate specific chemical reactions. They make life possible. For example, an enzyme found in saliva breaks up food for digestion on contact. With out this, it would take weeks for humans to digest our food.
Catalysts are also important in the laboratory as well as in manufacturing and industry. One of the most famous is the catalytic converter, which helps to prevent automobile emissions and make fuel consumption more efficient. Fertilizers are also catalysts that speed up plant growth.