CALVIN, MELVIN

born April 8, 1911, St. Paul, Minn., U.S. died Jan. 8, 1997, Berkeley, Calif. American biochemist who received the 1961 Nobel Prize for Chemistry for his discovery of the chemical pathways of photosynthesis. After graduating from the Michigan College of Mining and Technology (B.S., 1931) and the University of Minnesota (Ph.D., 1935), Calvin spent two years as a fellow of the Rockefeller Foundation at the University of Manchester, England. In 1937 he joined the faculty of the University of California at Berkeley, where in 1946 he became director of the bioorganic chemistry group at the Lawrence Radiation Laboratory; in 1971 he became university professor of chemistry. Pathway of carbon dioxide fixation and reduction in photosynthesis, the Calvin cycle. The diagram Calvin began his work on photosynthesis in the mid-1940s. For his studies he developed a system of using the radioactive isotope carbon-14 as a tracer element in the green alga Chlorella. By arresting the plant's growth at various stages and measuring the tiny amounts of radioactive compounds present, Calvin was able to identify most of the reactions involved in the intermediate steps of photosynthesis. His research also included work in radiation chemistry, the biochemistry of learning, processes leading to the origin of life, and using plant oils as a petroleum substitute.