This book is designed to be used as textbook for advanced undergraduate and graduate students in courses of microbial physiology and biochemistry, with a specific focus on the physiological processes in bacteria and archaea. This emphasis provides for the basis to explore bacterial and archaeal growth, as well as the response of these cells to the environment and to evaluate the enzymology used to support life at the cellular level. Building on the success of the first edition, the topics have been strengthened by the addition of new information and a reorganization which has resulted in condensed chapters to enable instructors to more readily adapt the various units of this book to their class schedules.  A set of questions is provided for each chapter and these questions can serve as in-class discussions or homework projects.  Through an extensive use of references, the reader is able to readily identify the source for material presented and this approach enables the book to also serve as a reference for research scientists. Through the use of updated figures and tables, details in the text are provided for the reader.  It is the hope that this book will summarize the current understanding of structure-function relationships in prokaryotes and to serve as a bridge to future developments in this area of microbiology.