Photosynthesis Calvin Cycle 2

Question 1

Which enzyme catalyzes the carboxylation of RuBP in the Calvin cycle?

Accepted Answer

RuBisCO

Answer

Phosphoglycerate kinase

Answer

Glyceraldehyde-3-phosphate dehydrogenase

Answer

Rubisco activase

Question 2

How many turns of the Calvin cycle are needed to produce one molecule of glucose?

Accepted Answer

6

Answer

3

Answer

12

Answer

18

Question 3

What is the oxidation state of carbon in CO₂ compared to the carbon in G3P?

Accepted Answer

CO₂ is more oxidized than G3P

Answer

CO₂ is more reduced than G3P

Answer

Both have the same oxidation state

Answer

G3P is more oxidized than CO₂

Question 4

Which phase of the Calvin cycle directly consumes ATP without consuming NADPH?

Accepted Answer

Regeneration of RuBP

Answer

Carbon fixation

Answer

Reduction

Answer

All phases use ATP equally

Question 5

What would happen to the Calvin cycle if NADPH were suddenly unavailable?

Accepted Answer

3-PGA would accumulate and G3P production would halt

Answer

Carbon fixation would stop immediately

Answer

RuBP would accumulate

Answer

ATP synthesis would increase to compensate

Question 6

Which metabolite is considered both a product and a reactant within the Calvin cycle?

Accepted Answer

RuBP

Answer

G3P

Answer

3-PGA

Answer

CO₂

Question 7

In the Calvin cycle, what is the direct product formed when RuBP reacts with CO₂?

Accepted Answer

Two molecules of 3-PGA

Answer

One molecule of 6-carbon sugar

Answer

One molecule of G3P and one CO₂

Answer

Two molecules of RuBP