10.2 Introduction to biological molecules

Introduction

The most fundamental difference between compounds of low molecular weight and macromolecular compounds resides in the fact that the latter may exhibit properties that cannot be deduced from a close examination of the low molecular weight materials. Not very different structures can be obtained from a few building blocks, but if 10,000 or 100,000 bloocks are at hand, the most varied structures become possible...

Biological macromolecules are large molecules, necessary for life (Table 1), and these large molecules are made from smaller organic molecules. As noted above, there is an almost infinite variety of possible structures for macromolecules, since both the composition and the bonds lining the components can vary tremendously. There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids). As we explore these molecules, think about how each class makes up important cell components and perform a wide array of functions. Since all these biological macromolecules contain carbon, we call them are organic molecules. In addition, the ratio of carbon, hydrogen, oxygen, nitrogen, and additional minor elements determines the class of biological molecules.