The Nobel Prize in Chemistry 1961 was awarded to Melvin Calvin "for his research on the carbon dioxide assimilation in plants".
 

It becomes obvious that photosynthesis not only provides an explanation for the existence of the autotrophic organisms but also furnishes food for man and animals. More than fifty years ago it was recognized that photosynthesis comprised two distinct phases, light reactions and dark reactions. Dr. Melvin Calvin, has spent many years of research work on the chemistry of both phases of photosynthesis and, in the case of the second phase, that is to say the reactions leading from carbon dioxide to the assimilation products - to quote Calvin, "the path of carbon in photosynthesis" his work has resulted in the complete clarification of an extremely intricate problem.