enzymes that are unique to the Calvin cycle along with their substrates, products, and any co-factors that are required for their activity.

1) List the three enzymes that are unique to the Calvin cycle along with their

substrates, products, and any co-factors that are required for their activity.

2) Sketch the detailed chemical mechanism of ribulose-1,5-bisphophate as it reacts

with carbon dioxide to generate two molecules of 3-phosphoglycerate by the

ribulose-1,5-bisphophate carboxylase (rubisco) enzyme.

3) The overall equation for photosynthetic CO

2 fixation is:

6 CO

2 + 6 H2O –> C6H12O6 + 6 O2

All

of the O atoms evolved as O2 come from water; none comes from carbon

dioxide. But 12 O atoms are evolved as 6 O

2, and only 6 O atoms appear as 6

H

2O in the equation. Also, 6 CO2 have 12 O atoms, yet there are only 6 O atoms

in C

6H12O6. How can you acccount for these discrepancies? (Hint: what three

reactions are carried out during the dark reactions?)