Living cells contain two forms of nucleic acid-deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It has been known for a number of years that RNA molecules are involved in the expression of the genetic material (DNA) and are, in fact, the initial products of gene expression that go on to direct protein synthesis. Knowledge of the structure, metabolism, and mode of action of RNA in protein synthesis is therefore fundamental to our understanding of the control of gene expression, cell division, growth, and development. Furthermore, the recent spectacular advances in genetic engineering depend on a working knowledge of RNA synthesis and its control.
