CALVIN CYCLE AP BIO

Calvin Cycle

In the stroma without light, needs energy from NADPH and ATP to convert CO2 into sugar

Calvin Cycle Reactants (for one round)

3 CO2

9 ATP

6 NADPH

How much carbons are involved?

18 carbons (3 RuBPs = 15 carbons, 3 CO2)

3 phases of Calvin Cycle

Carbon fixation, reduction, regeneration

Carbon fixation

CO2 is combined with RuBP, catalyzed by RuBisCo enzyme

Creates a six carbon product that dissolves into two 3 carbon molecules (PGA)

Reduction phase

3 carbon product of carbon fixation is phosphorylated (ATP -- ADP), and reduced (NADPH - NADP+)

Creates G3P

Why is G3P created?

It has much more energy than PGA, through NADPH and ATP

G3Ps after reduction

1 G3P used, 5 others are saved for recycling later

Recycle

5 G3Ps are arranged into 3 5-carbon RuBPs

Phosphorylation occurs along the way, creates substrate for carbon fixation