Few students complete an introductory biology course without learning about the Krebs cycle, an indispensable step in the process the body performs to convert food into energy. Also known as the citric acid cycle or tricarboxylic acid cycle, the Krebs cycle derives its name from one of the most influential biochemists of our time. Born in the same year as the twentieth century, Hans Adolf Krebs spent the greater part of his eighty-one years engaged in research on intermediary metabolism. First rising to scientific prominence for his work on the ornithine cycle of urea synthesis, Krebs shared the Nobel Prize for physiology and medicine in 1953 for his discovery of the citric acid cycle. Over the course of his career, the German-born scientist published, oversaw, or supervised a total of more than 350 scientific publications. But the story of Krebs's life is more than a tally of scientific achievements; his...