Assuming a quantum requirement for photosynthesis of 8 (8 photons), calculate a thermodynamic efficiency in percent under standard conditions for the conversion of carbon dioxide to 3-phosphogylcerate if the wavelength of light used in 400 nm. To produce one mole of glucose from carbon dioxide and water requires +686 kcal of energy (6 CO2 + 6 H2O ! 1 C6H12O6 + O2). Hint: First calculate the number of kcal required to reduce one molecule of carbon dioxide to 3-phosphoglycerate during step one of the Calvin cycle.