ABSTRACT
Enzymes are biological catalysts. They increase the rate of chemical reactions taking place within living cells, without themselves suffering any overall change. In fact, these are central to life, and it may not be an understatement to say that these molecules sustain life on this planet. Most of the enzymes are proteins, to be more specific globular proteins. Since, some RNAs are also known to act as biocatalysts, it is not correct to say that all enzymes are proteins, but for these few exceptions, all enzymes are proteins. More specifically it can be defined as a polypeptide chain or an ensemble of polypeptide chains possessing a catalytic activity in its native form. The reactants of an enzymecatalyzed reaction are called substrates. The catalysis takes place in a specific region of the enzyme, referred to as the active center or catalytic cavity. Most of the enzymes use a nonprotein component called a cofactor for bringing about this catalytic activity.
