tailieunhanh - Ebook Physical chemistry for the life sciences (2nd edition): Part 2

(BQ) Part 2 book "Physical chemistry for the life sciences" has contents: Microscopic systems and quantization, the chemical bond, macromolecules and self-assembly, optical spectroscopy and photobiology, magnetic resonance. | PART 3 Biomolecular structure We now begin our study of structural biology, the description of the molecular features that determine the structures of and the relationships between structure and function in biological macromolecules. In the following chapters, we shall see how concepts of physical chemistry can be used to establish some of the known ‘rules’ for the assembly of complex structures, such as proteins, nucleic acids, and biological membranes. However, not all the rules are known, so structural biology is a very active area of research that brings together biologists, chemists, physicists, and mathematicians. This page intentionally left blank 9 Microscopic systems and quantization The first goal of our study of biological molecules and assemblies is to gain a firm understanding of their ultimate structural components, atoms. To make progress, we need to become familiar with the principal concepts of quantum mechanics, the most fundamental description of matter that we currently possess and the only way to account for the structures of atoms. Such knowledge is applied to rational drug design (see the Prolog) when computational chemists use quantum mechanical concepts to predict the structures and reactivities of drug molecules. Quantum mechanical phenomena also form the basis for virtually all the modes of spectroscopy and microscopy that are now so central to investigations of composition and structure in both chemistry and biology. Present-day techniques for studying biochemical reactions have progressed to the point where the information is so detailed that quantum mechanics has to be used in its interpretation. Atomic structure—the arrangement of electrons in atoms—is an essential part of chemistry and biology because it is the basis for the description of molecular structure and molecular interactions. Indeed, without intimate knowledge of the physical and chemical properties of elements, it is impossible to understand the molecular basis .