To fix 6 molecules of CO ₂ in the Calvin cycle, what is the number of ATP molecules utilized strictly in the reduction phase and the regeneration phase, respectively?

Step-by-step solution

In the Calvin cycle, the fixation of a single CO ₂ molecule requires 2 ATP molecules during the reduction phase and 1 ATP molecule during the regeneration of RuBP. For the fixation of 6 molecules of CO ₂ (equivalent to the synthesis of one glucose molecule): ATP utilized in the reduction phase = 6 2 = 12 ATP utilized in the regeneration phase = 6 1 = 6 Therefore, 12 ATP molecules are used in reduction and 6 ATP molecules are used in regeneration. Students often confuse the per CO ₂ requirement (2 and 1) with the to