Question

For the synthesis of one glucose molecule the calvin cycle operates for:

• A. 2 times
• B. 4 times
• C. 6 times
• D. 8 times

Answer 1

The Correct Option is C

The Calvin Cycle, also known as the C₃ cycle or the Calvin-Benson-Bassham (CBB) cycle, is a crucial part of the photosynthesis process in plants. It is responsible for synthesizing glucose by fixing carbon dioxide, and it occurs in the stroma of chloroplasts. To synthesize one molecule of glucose (C₆H₁₂O₆), the Calvin Cycle needs to complete multiple rounds. Let's delve into the step-by-step explanation:

1. Understanding the Calvin Cycle:
   • The Calvin Cycle comprises three phases: Carbon fixation, Reduction phase, and Regeneration of Ribulose 1,5-bisphosphate (RuBP).
   • One molecule of carbon dioxide is fixed per cycle to eventually produce a sugar molecule of glyceraldehyde-3-phosphate (G3P).
2. Requirement for One Glucose Molecule:
   • To synthesize one G3P molecule, the cycle must turn three times, fixing three molecules of CO₂.
   • However, glucose is a six-carbon sugar, hence two G3P molecules are required for one glucose molecule.
   • This means that the cycle must operate a total of six times to produce one glucose molecule.
3. Conclusion:
   • For the synthesis of one glucose molecule, the Calvin cycle operates for 6 cycles.

Hence, the correct answer is 6 times.