Enzymes

DNA appears to be solely concerned with the formation of protein. A gene may be defined as that part of a DNA molecule involved in controlling the production of proteins. In general, there are two kinds of proteins: structural proteins and enzymes. Other constituents of cells, such as cellulose, lignin, suberin, hormones, and starch, are manufactured by the aegis of enzymes. Although not all proteins are enzymes, all enzymes are proteins; and many different kinds of enzymes are involved in protein synthesis. Specific enzymes, for example, are required to uncoil DNA. Other kinds of enzymes are called on to replicate DNA, while still others are needed to form m-RNA. Certain enzymes are required to connect amino acids to form polypeptides. All life processes are controlled by enzymes, and a single cell may have several thousands of kinds of enzymes. Enzymes are highly specific, a particular kind of enzyme typically catalyzing a particular reaction.