compounds. 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.
He married Genevieve Jemtegaard in 1951, and
they had two daughters and a son.
In his final years of active research, he studied the
use of oil-producing plants as renewable sources of
energy and spent years testing the chemical evolution
of life.
Throughout his distinguished career, Calvin
received many awards and honors, including the
National Medal of Science, which he received from
President Bush in 1989; the Priestley 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 died on January 9, 1997, at Alta Bates Hos-
pital in Berkeley, California, after a long illness.Calvin cycle Discovered by chemist Melvin Calvin
(1911–97), it is the second major stage in photosynthe-
sis after light reactions whereby carbon molecules from38 Calvin cycle
American biochemist Melvin Calvin (born 1911). In the 1950s, Calvin used radioactive isotopes to elucidate the chemical details of the
process of photosynthesis. He won the Nobel Prize in chemistry in 1961. The photograph was taken at the University of California at
Berkeley, where Calvin directed the chemical biodynamics laboratory in the Lawrence Radiation Laboratory (later the Lawrence
Berkeley Laboratory).(Courtesy of Lawrence Berkeley Laboratory/Science Photo Library)