Which event in the Calvin cycle would be the LEAST affected by a malfunction in the electron transport system?
A. synthesis of G3P
B. production of ADP
C. regeneration of RuBP
D. production of 3-PGA
To determine which event in the Calvin cycle would be the least affected by a malfunction in the electron transport system, we first need to understand the role of the electron transport system in the Calvin cycle.
The Calvin cycle is a series of biochemical reactions that occur in the chloroplasts of plants during photosynthesis. It is responsible for converting carbon dioxide (CO2) into glucose (C6H12O6). The electron transport system plays a crucial role in the Calvin cycle by providing the necessary energy through the transfer of high-energy electrons.
Now let's analyze the options:
A. Synthesis of G3P (glyceraldehyde-3-phosphate): This step involves the reduction of 3-phosphoglycerate (3-PGA) using energy and electrons from NADPH (produced in the electron transport system). Therefore, a malfunction in the electron transport system would likely impact the synthesis of G3P.
B. Production of ADP (adenosine diphosphate): ADP is not directly involved in the Calvin cycle, and its production is not influenced by the electron transport system. Therefore, a malfunction in the electron transport system would not affect the production of ADP.
C. Regeneration of RuBP (ribulose 1,5-bisphosphate): This step involves the rearrangement of molecules and requires energy from ATP, which is produced in the electron transport system. Therefore, a malfunction in the electron transport system would likely impact the regeneration of RuBP.
D. Production of 3-PGA (3-phosphoglycerate): 3-PGA is the first stable product of carbon fixation in the Calvin cycle and does not directly depend on the electron transport system. Therefore, a malfunction in the electron transport system would not affect the production of 3-PGA.
Based on this analysis, the event in the Calvin cycle that would be the least affected by a malfunction in the electron transport system is the production of 3-PGA (Option D).