What Is the Importance of Enzymes?

Enzymes are molecules that serve as catalysts for reactions. That is, reactions happen more quickly and efficiently when enzymes are present. In many cases, enzymes promote reactions that may not be possible under normal circumstances.

Significance

Without enzymes, most physiological processes would not take place. Hundreds of different types of enzymes are present in plant and animal cells and each is very specific in its function.

Function

An enzyme works on a substrate to change the substrate in some way. Under normal circumstances, energy (known as the energy of activation) is required to undergo this change. Enzymes lower the energy of activation so that the reaction requires less energy. This makes the reactions occur more readily and at a potentially faster rate.

History

In 1894, Emil Fischer discovered that enzymes are very specific for the substrate on which they work and the reactions they promote. He named this specificity the "lock and key" model. Since that time, enzymes have been found to be more flexible, and able to change shape slightly to fit substrates.

Identification

Most enzymes are named with the suffix --ase on the ending. The first part of the enzyme's name denotes the substrate on which the enzyme works. For instance, protease enzymes help the digestive system break down proteins, while cellulase breaks down cellulose within plant cell walls.

Considerations

Enzyme activity can be affected by external factors, such as the presence of a chemical and in temperature, pH, or ultraviolet radiation extremes. These external factors can destroy the protein structure of the enzyme, rendering it useless. This is one reason high fevers can be lethal.