The Clavin Cycle

Question 1

Step 2 in Calvin cycle

Answer 1

Reduction reaction
Each of the 6 molecule of PGA is phosphorylated by ATP to form 6 molecule of 1-3 BPG
A pair of e’s from each of the 6 NADPH molecules reduces 6 molecules of 1-3 BPG to G3P

Question 2

Step 3 in the Calvin cycle

Answer 2

Regeneration of RuBP

In the final stage the remaining 5 G3Ps enter into in a series of enzyme-catalyzed reactions are re arranged into RuBP
With RuBP regenerated the cycle may fit more co2 molecules are fixed the G3P molecules will leave and be synthesized into larger sugars. 3 CO2 must be fixed before one G3P molecule can be removed

Question 3

Step 1 in Calvin cycle

Answer 3

Carbon fixation

CO2 adds to the existing 5 carbon molecule RuBP to form an unstable 6-carbon
This carbon immediately splits into 3PGA
These are catalyzed by rubisco (exergonic reaction)