Microbial physiology, biochemistry and genetics allowed the formulation of concepts that turned out to be important in the study of higher organisms. In the first section, the principles of bacterial growth are given, as well as the description of the different layers that enclose the bacterial cytoplasm, and their role in obtaining nutrients from the outside media through different permeability mechanism described in detail. A chapter is devoted to allostery and is indispensable for the comprehension of many regulatory mechanisms described throughout the book. Another section analyses the...