The nature of enzymes

Enzymes are complex globular proteins present in living cells where they act as catalysts that facilitate chemical changes in substances. In 1878 Kühne introduced the term ‘enzyme’ from the Greek enzumos, which refers to the leavening of bread by yeast. With the development of the science of biochemistry has come a fuller understanding of the wide range of enzymes present in living cells and of their modes of action. Without enzymes there can be no life. Although enzymes are only formed in living cells, many can be extracted or separated from the cells and can continue to function in vitro. This unique ability of enzymes to perform their specific chemical transformations in isolation has led to an ever-increasing use of enzymes in industrial and food processes, bioremediation and in medicine, and their production is collectively termed enzyme technology.

The activity of an enzyme is due to its catalytic nature. An enzyme carries out its activity without being consumed in the reaction, while the reaction occurs at a very much higher rate when the enzyme is present. Enzymes are highly specific and function only on designated types of compounds, the substrates. A minute amount of enzyme can react with a large amount of substrate. The catalytic function of the enzyme is due not only to its primary molecular structure but also to the intricate folding configuration of the whole enzyme molecule.