2.2.3 Light Independent Stage

Question 1

What is the first step in the light-independent stage?

Answer 1

Carbon fixation.

This involves CO2 combining with RuBP.

Question 2

What does CO2 combine with during carbon fixation?

Answer 2

Five 5-carbon acceptor molecules, RuBP.

This reaction is catalyzed by the enzyme rubisco.

Question 3

What happens to the 6-carbon compound formed during carbon fixation?

Answer 3

It splits into 2 3-carbon compounds.

This is a crucial step in forming sugars.

Question 4

What occurs during the reduction phase of the light-independent stage?

Answer 4

NADPH donates electrons to the 3-carbon compound.

This process converts the compound into high-energy sugars.

Question 5

What happens to one of the 3-carbon compounds in the regeneration phase?

Answer 5

It goes to make glucose.

This is essential for energy storage in plants.

Question 6

What is required for the regeneration of RuBP?

Answer 6

ATP.

This phase involves a complex network of reactions.

Question 7

What are the inputs for the light-independent stage?

Answer 7

6 O2, 12 NADPH, 18 ATP.

These are the outputs from the light-dependent stage.

Question 8

What are the outputs of the light-independent stage?

Answer 8

C6H12O6, 12 NADP+, 18 ADP+Pi, 6 H2O.

Glucose produced is a primary energy source for plants.