Cycles, biological Calvin

The assembly of biological molecules, including proteins and nucleic acids, requires the generation of appropriate starting materials. We have already considered the assembly of carbohydrates in regard to the Calvin cycle and the pentose phosphate pathway (Chapter 20). The present chapter and the next two examine the assembly of the other important building blocks—namely, amino acids, nucleotides, and lipids. 

Calvin dark cycle pathway a pathway of biological CO2 fixation in which early products are C3 compounds. 

Since conserved strnctures with a very long lifetime have a great advantage in the evolution, a biological system is used over and over again. The result is cyclic reactions where reactants are fed in along a pathway and products are given away. There are several examples in Natnre, for example, the citric acid cycle and the Calvin cycle. 

Calvin, Melvin (1911-97) American chemist. Calvin worked out the biological mechanisms that occur in photosynthesis. He used techniques such as chromatography and radioisotopes to study the reactions of photosynthesis that do not require light. He found that there is a series of reactions, now known as the Calvin cycle. Calvin summarized his findings in a work entitled The Path of Carbon in Photosynthesis (1957). Calvin won the 1961 Nobel Prize for chemistry for his work on photosynthesis. He continued to work on various problems associated with photosynthesis. 

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