Which compound is produced during carbon fixation? 3-PGA G3P RuBP C6H12O6
The Correct Answer and Explanation is:
The compound produced during carbon fixation is 3-PGA (3-phosphoglycerate).
Explanation:
Carbon fixation occurs during the Calvin cycle, which is a part of photosynthesis in plants. The process of carbon fixation involves the enzyme RuBisCO (ribulose bisphosphate carboxylase/oxygenase) combining carbon dioxide (CO2) from the atmosphere with a 5-carbon molecule called RuBP (ribulose bisphosphate). This reaction produces an unstable 6-carbon intermediate, which quickly breaks down into two molecules of 3-PGA (3-phosphoglycerate), a 3-carbon compound.
Here’s the process in more detail:
- Carbon fixation: CO2 enters the plant’s leaf cells through the stomata and is captured by RuBP. RuBisCO catalyzes this reaction, forming a short-lived 6-carbon compound.
- Splitting of the 6-carbon compound: The 6-carbon intermediate rapidly breaks down into two molecules of 3-PGA.
- Reduction: The 3-PGA molecules are then converted into G3P (glyceraldehyde-3-phosphate) using ATP and NADPH, which were generated in the light-dependent reactions of photosynthesis.
- Regeneration: Some G3P molecules are used to regenerate RuBP, allowing the cycle to continue. The rest of the G3P can be used to form glucose or other carbohydrates.
So, 3-PGA is the immediate product of carbon fixation and serves as the first stable product in the Calvin cycle. It is subsequently converted into other important organic molecules like G3P (which can eventually form glucose, C6H12O6).
To summarize, 3-PGA is the compound produced during carbon fixation in the Calvin cycle of photosynthesis.
