Chemical biology is born out of a desire to understand the molecular basis of life. What are the molecules found in cells? How do their intrinsic properties equip them to perform all the complex processes found in cells? This book introduces the fundamental chemistry of the molecules that are essential to all cells. The molecules covered include amino acids and sugar phosphate derivatives, and the macromolecules derived from them (proteins and nucleic acids respectively). In such a short text it is not possible to provide a comprehensive account of the chemistry of these molecules; instead this book introduces important concepts concerning their intrinsic chemistry. The aim is to provide the fundamental ideas relating to the chemistry of life that can then be applied to more advanced aspects of chemical biology.