Which of the following is a product of the Calvin cycle of photosynthesis?

• A. Oxygen (\(O_2\))
• B. NADPH
• C. ATP
• D. Glyceraldehyde-3-phosphate (G3P)

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the Calvin cycle, which is the light-independent reaction of photosynthesis. It occurs in the stroma of chloroplasts and uses ATP and NADPH produced during the light-dependent reactions to fix carbon dioxide (\(CO_2\)) into organic molecules.
2. Step 2: Recognize that the Calvin cycle consists of three main phases: carbon fixation, reduction, and regeneration of ribulose-1,5-bisphosphate (RuBP). During carbon fixation, \(CO_2\) is attached to RuBP by the enzyme RuBisCO, forming 3-phosphoglycerate (3-PGA).
3. Step 3: In the reduction phase, ATP and NADPH are used to convert 3-PGA into glyceraldehyde-3-phosphate (G3P). This is the key product of the Calvin cycle, which can be used to form glucose and other carbohydrates.
4. Step 4: Understand that oxygen (\(O_2\)), NADPH, and ATP are not direct products of the Calvin cycle. Oxygen is released during the light-dependent reactions, while NADPH and ATP are consumed during the Calvin cycle to drive the reactions.
5. Step 5: Conclude that glyceraldehyde-3-phosphate (G3P) is the correct answer because it is the primary carbohydrate product of the Calvin cycle, which can be used for energy storage and biosynthesis in the plant.