Discovery of the Calvin cycle, also known as the Calvin–Benson–Bassham (CBB) cycle, or reductive pentose phosphate cycle or C3 cycle — a series of biochemical redox reactions that take place in the stroma of chloroplast in photosyntheticorganisms. This is also known as the light-independent reactions. The series of discoveries were first reported in a series of 21 papers from 1948 to 1954. The first, with Andrew. A. Benson was "The path of carbon in photosynthesis", Science, 107 (1948) 476-480. The last, with J. A. Bassham, A. A. Benson , L. D. Kay, A. Z. Harris, and A.T. Wilson was "The path of carbon in photosynthesis XXI. The cyclic regeneration of carbon dioxide acceptor in photosynthesis," J. Am. Chem. Soc.,76 (1954)1760--1770. See Melvin Calvin 1911-1996, A biographical memoir by Glenn T. Seaborg and Andrew A. Benson, Washington, D.C. National Academies Press, 1998.

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