| the phase of photosynthesis, not requiring light, in which carbohydrates are synthesized from carbon dioxide. |
| dark reaction n. The second stage of photosynthesis, not requiring light to occur, and during which energy released from ATP drives the production of organic molecules from carbon dioxide. |
| dark reaction
Any of the chemical reactions that take place during the second stage of photosynthesis and do not require light. During the dark reactions, energy released from ATP (created by the light reactions) drives the fixation of carbon from carbon dioxide in organic molecules. The Calvin cycle forms part of the dark reactions. As long as ATP is available, the dark reactions can occur in darkness or in light. Compare light reaction. See more at Calvin cycle, photosynthesis. |