Unit 3 Light-Independent Reactions

What do light-independent reactions not require?

Sunlight

What are alternative names for light-independent reactions?

Dark reactions or Calvin cycle

Where do light-independent reactions occur?

Stroma of chloroplasts

What are the inputs of light-independent reactions?

NADPH, ATP, and CO₂

What are the outputs of light-independent reactions?

ADP and unhooked phosphate group, NADP+, and glucose

What is the main function of light-independent reactions?

To use energy-carrying molecules from light-dependent reactions and carbon dioxide to make glucose 3

What is produced from one turn of the Calvin cycle?

3-C carbohydrate called glyceraldehyde 3 phosphate (G3P) or PGAL

What can PGAL be joined with to make?

Glucose or another organic compound

What does the Calvin cycle represent?

Fixation of three carbon dioxide molecules or three turns of the chemical cycle

What is the first step of the Calvin cycle?

3 CO₂ molecules come into the plant through the stomata and diffuse into the chloroplast

How is carbon in CO₂ “fixed?”

By attaching to 3 recycled 5-carbon compounds called RuBP

What attaches the carbon in CO₂ to RuBP?

The enzyme rubisco 

What is created when carbon from CO₂ attaches to RuBP?

3 unstable 6-C compounds

What do the 3 unstable 6-C compounds almost immediately break in half to create?

6, 3-C compounds called PGA (phosphoglycerate)

What is PGA reduced by?

ATP

What is PGA reduced to form?

6- 1, 3-biphosphoglycerate

What is the 6- 1, 3-biphosphoglycerate further reduced by?

Electrons from NADPH

What is formed when 6- 1, 3-biphosphoglycerate is further reduced?

6, 3-C compounds called PGAL (G3P)

What will leave the Calvin cycle?

1 PGAL

What will the PGAL that leaves the Calvin cycle later form?

Glucose by combining with another PGAL

What remains in the Calvin cycle?

5 PGALs

What are the 5 PGALs rearranged into?

3 RUBP

What helps rearrange the 5 PGALs?

ATP

Why are the 5 PGALs rearranged into RuBP?

To start the Calvin cycle again