Calvin, Melvin (1911–1997)
US chemist who was awarded the Nobel Prize for Chemistry in 1961 for his study of the assimilation of carbon dioxide by plants. Using radioactive carbon-14 as a tracer, he determined the biochemical processes of photosynthesis, in which green plants use chlorophyll to convert carbon dioxide and water into sugar and oxygen.
| Calvin was born in St Paul, Minnesota, and studied at Michigan College of Mining and Technology and the University of Minnesota. From 1937 he was on the staff of the University of California, becoming professor in 1947. |
| Calvin began work on photosynthesis in 1949, studying how carbon dioxide and water combine to form carbohydrates such as sugar and starch in a single-celled green alga, Chlorella. He showed that there is in fact a cycle of reactions (now called the Calvin cycle) involving an enzyme as a catalyst. |
