Dark Reactions

Aka - Light Independent Reactions, Calvin Cycle, Carbon Fixation

light

ATP can be made without ? as long as H⁺ ions are pumping in and out the chloroplast’s lumen

Carbon Fixation, Reduction, Regeneration

3 things happening in Calvin Cycle

ATP, NADPH

Calvin cycle relies on ? and ? from the Light Reactions

G3P

Product of Calvin Cycle

any

G3P can be used to make ? carbon compound

• lipids, carbohydrates, proteins

1st Step

15 Carbons in the from of 3 RuBP take in 3 CO₂

2nd Step

The 3 CO₂ break apart and the 3 Carbons fix themselves with the 3 RuBP to make 6 groups of 3 Carbon chains

3rd Step

One group of 3 Carbons from the 6 groups of 3 Carbon chains leaves and becomes G3P

4th Step

The remaining 5 groups of 3 Carbon chains reform to become 3 RuBP again

RuBisCo

Ribulose-1,5-biphosphate carboxylase-oxygenase

• enzyme that fixes CO₂ in the Calvin Cycle

Photorespiration

RuBisCO has an equal affinity for CO₂ and O₂

• problematic in hot, dry environments when stomata must close

• O₂ will build up in the tissue of the leaf

competitive

O₂ is a ? inhibitor of RuBisCO

C4 Plants

Anatomically separate steps of Carbon fixation in 2 different cells to prevent photorespiration

CAM Plants

Temporally separates 2 steps of Carbon fixation into 2 different times of day (night vs day)