During the last decade physical and chemical methods have improved rapidly - a fact which allowed the mode of action of antibiotics to be studied - and many biochemically-oriented scientists have devoted their research to the following questions: 1. What is the metabolic pathway that is inhibited selectively, and what are the target molecules within a sensitive cell? 2. What are the relationships between the chemical structure of an antibiotic and the physicochemical properties of the sensitive mole cule(s)? 3. Why and how far is the action selective? 4. Is it possible to correlate the...