The Emergence of the Concept of Macromolecule

Abstract

AbstractThe concept of biological macromolecule emerged in the first half of the 20th century and was the product of overcoming two epistemological obstacles: the possibility of having such large molecules held together by normal chemical bonds and the obstacle created by aperiodic polymers. The emergence of the concept of the aperiodic polymer, which is made up of several repeating units, is one of the ideas that grounds the concept of the biological macromolecule. In this chapter, we will begin by discussing the protoplasmic theory and the theory of the colloidal state, and continue with the role that two new experimental techniques, the X-ray and the ultracentrifuge, played in helping early-20th-century biochemists approach the new concept of macromolecules. We will then analyze the general problem of protein folding, the role of the environment, and the use of statistics and self-organization aspects in this process. Finally, we will highlight the difference between the concepts of structure and of shape in molecules and macromolecules.