Question

Net synthesis of 1 G3P fixes how many molecules of CO₂?

Answer 1

During the Calvin cycle, it takes three “turns” to fix enough carbon dioxide to produce one G3P molecule. The net synthesis of 1 G3P fixes 3 molecules of CO₂.

Step-by-step explanation:

During the Calvin cycle, it takes three “turns” to fix enough carbon dioxide to produce one G3P molecule. Each turn of the cycle produces two G3P molecules, so three turns produce six G3P molecules in total. However, only one G3P molecule is exported from the chloroplast, while the remaining five G3P molecules are used to regenerate RuBP for the continuation of the cycle. Therefore, the net synthesis of 1 G3P fixes 3 molecules of CO₂.