A Man of Exceptional Curiosity

By Lynn Yarris

One of Berkeley Lab's greatest scientists, Melvin Calvin, the man who unlocked the secrets of photosynthesis, died on January 7, 1997, after years of failing health. He was 85.

A member of the faculty at UC Berkeley since 1937, and one of the first chemists to join Ernest O. Lawrence's Radiation Laboratory, Calvin received the 1961 Nobel prize in chemistry for identifying the path of carbon in photosynthesis. Shortly thereafter he established the Chemical Biodynamics Division, the successor to today's Structural Biology Division, which he directed for 20 years.

Throughout his distinguished career, Calvin was the recipient of a great many awards and honors, including the National Medal of Science, which he received from President Bush in 1989, the Priestly Medal from the American Chemical Society, the Davy Medal from the Royal Society of London, and the Gold Medal from the American Institute of Chemists.

Calvin was born on April 8, 1911 in Saint Paul, Minnesota. He earned his undergraduate degrees from the Michigan College of Mining and Technology in 1931 and his Ph.D. in chemistry from the University of Minnesota in 1935. Following post-doctoral studies at the University of Manchester in England, Calvin was invited to join the UCB faculty by the illustrious chemist Gilbert Lewis who introduced him to Ernest Lawrence. According to legend, on the day of the Japanese surrender, Lawrence told Calvin, "Now is the time to do something useful with radioactive carbon," the isotope of carbon that had been discovered in 1940 at the 60-Inch Cyclotron. In response, Calvin organized a team of Rad Lab researchers to study photosynthesis, the process by which green plants convert sunlight energy into chemical energy, releasing oxygen into the atmosphere.

Calvin in the old Radiation Laboratory with the apparatus used in his groundbreaking work on photosynthesis. His research earned him the 1961 Nobel Prize in Chemistry.
Photosynthesis involves a complex series of reactions that are extremely difficult to study. Not only are the reactions rapid and short-lived, the process can only take place in living plant cells, which means scientists cannot directly study extracts or processed samples. Using the carbon-14 isotope as a tracer, and analytic techniques he'd acquired during his war-time contributions to the Manhattan Project, Calvin began working with single-cell green algae.

The experiment was slow and painstaking. Leaf cells of the algae would be exposed for a few seconds at a time to carbon dioxide that had been tagged with radiocarbon. The leaves would then be immersed in boiling alcohol so that whatever compounds had been synthesized during the exposure to carbon dioxide could be extracted and identified. By 1957 Calvin and his group had mapped the complete route that carbon travels through a plant during photosynthesis, starting from its absorption as atmospheric carbon dioxide to its conversion into carbohydrates and other organic compounds. In doing so, they showed that sunlight acts on the chlorophyll in a plant to fuel the manufacturing of organic compounds, rather than on carbon dioxide as was previously believed.

Calvin was dubbed "Mr. Photosynthesis" by TIME Magazine when it reported his Nobel prize triumph. A repeating chain of critical intermediate reactions in the photosynthetic process was named the "Calvin cycle." His Nobel laureate fame won him a place on the President's Science Advisory Commit- tee under presidents Kennedy and Johnson, and he was picked to chair the National Academy of Science's prestigious Committee on Science and Public Policy.

As a scientist, Calvin's Nobel prize-winning research led to a lifelong interest in adapting photosynthetic techniques for energy production. He is credited by the U.S. Department of Energy with spurring the start of its solar energy research programs. In his final years of active research, Calvin studied the use of oil-producing plants as renewable sources of energy. He also spent many years testing the chemical evolution of life and wrote a book on the subject that was published in 1969.

Melvin Calvin in front of the laboratory on the UC Berkeley campus named in his honor.
Like Lawrence, Calvin was a devout believer in interdisciplinary collaborations. For his photosynthesis research, he and his group worked in the wooden building that had served as Lawrence's original Radiation Laboratory. When this turn-of-the-century structure was torn down in 1959, its "laboratory without walls" concept inspired Calvin in the unique design of a new building on the UCB campus to house his group. Opened in 1963, the three-story construction featured a distinctive doughnut-shaped exterior and an open interior with radial lab benches, all of which were intended to foster the cooperative teamwork that Calvin preached and practiced. Upon his retirement in 1980, the building, which houses the Structural Biology Division research-ers today, was renamed the Melvin Calvin Laboratory.

As a tribute to Calvin's accomplishments, the Laboratory named one of its nine roads in his honor. Calvin provided his own epithet in two separate interviews by reporters who asked him what it was that kept him going through the many years it took to unravel the mystery of photosynthesis, and the years he spent seeking to harness the process for human energy needs.

"My curiousity about science and how the world works," was Calvin's answer on both occasions.