[Campbell Biology P.251] According to Figure 10.18 and its description, what is the fate of ... | Practice Question
According to Figure 10.18 and its description, what is the fate of the carbon atoms that enter the Calvin cycle, and how are the CO2 acceptor molecules regenerated?
A: 3 CO2 molecules enter, 1 G3P molecule leaves as net output, and the remaining 5 molecules of G3P are used to regenerate 3 molecules of RuBP.
B: 6 CO2 molecules enter, 2 G3P molecules leave as net output, and 4 molecules of G3P are used to regenerate 3 molecules of RuBP.
C: 3 CO2 molecules enter, 2 G3P molecules leave as net output, and 4 molecules of G3P are used to regenerate 5 molecules of RuBP.
D: 3 CO2 molecules enter, 1 G3P molecule leaves as net output, and 6 molecules of G3P are used to regenerate 3 molecules of RuBP.
Explanation
Figure 10.18 shows that 3 CO2 molecules enter the cycle. The text states that for every 3 molecules of CO2 that enter, the net output is one molecule of G3P. The diagram also illustrates that 5 molecules of G3P are rearranged to regenerate 3 molecules of RuBP, the CO2 acceptor.