High School

Which compound is produced during carbon fixation?

A. PGA
B. G3P
C. RuBP
D. C6H12O6

Answer :

During carbon fixation in the Calvin cycle, the compound produced is 3-phosphoglycerate (PGA). Here's a step-by-step explanation of how this process works:

1. Carbon Dioxide Uptake: Carbon fixation begins with the uptake of carbon dioxide (CO2) from the atmosphere.

2. Enzyme Involvement: The enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase, commonly known as RuBisCO, plays a key role in catalyzing the first major step of the cycle.

3. Reaction with RuBP: RuBisCO facilitates the reaction between CO2 and ribulose bisphosphate (RuBP), which is a 5-carbon sugar with two phosphate groups.

4. Formation of Intermediate: This reaction results in an unstable 6-carbon intermediate, which immediately splits to form two molecules of 3-phosphoglycerate (PGA).

Therefore, the compound produced during the carbon fixation phase of the Calvin cycle is PGA, making it the correct answer to the question.