ABSTRACT
The first hints of the chemical basis of life were noted approximately 150 years ago. Leading up to this initial awareness were a series of insights that living organisms comprise a hierarchy of structures: organs, which are composed of individual cells, which are themselves formed of organelles of different chemical compositions, and so on. From this realization and the observation that nonviable extracts from organisms such as yeast could by themselves catalyze chemical reactions, it became clear that life itself was the result of a complex combination of individual chemicals and chemical reactions. These advances stimulated investigations into the nature of the molecules responsible for biochemical reactions, culminating in the discovery of the genetic code and the molecular structure of deoxyribonucleic acid (DNA) in the early 1950s by Watson and Crick [1]. One of the most fascinating aspects of their discovery was that an understanding of the mechanism by which the genetic code functioned could not be achieved until knowledge of the threedimensional (3D) structure of DNA was attained. The discovery of the structure of DNA and its relationship to DNA function had a tremendous impact on all subsequent biochemical investigations, basically defining the paradigm of modern biochemistry and molecular biology. This established the primary importance of molecular structure for an understanding of the function of biological molecules and the need to investigate the relationship between structure and function in order to advance our understanding of the fundamental processes of life.
