Mississippi State Biology 1 Practice Test 2025 – Comprehensive Exam Prep

The Calvin cycle, also known as the light-independent reactions of photosynthesis, utilizes specific inputs to produce glucose and regenerate essential molecules. The correct choice includes carbon dioxide, NADPH, and ATP as the critical components needed for the cycle to function.

Carbon dioxide serves as the primary source of carbon that will ultimately be incorporated into organic molecules, specifically glucose. It enters the cycle through the stomata of leaves, where it is fixed by the enzyme RuBisCO, initiating the cycle.

NADPH and ATP are essential energy carriers produced during the light-dependent reactions of photosynthesis. NADPH provides the reducing power necessary for the conversion of 3-phosphoglycerate into glyceraldehyde-3-phosphate, a three-carbon sugar that is a building block for glucose. ATP supplies the energy required for various steps in the Calvin cycle, including the regeneration of ribulose bisphosphate (RuBP), which is crucial for allowing the cycle to continue.

Combining these components, the Calvin cycle effectively transforms carbon dioxide into carbohydrate fuels by utilizing energy and reducing power stored during the light-dependent reactions. This intricate process is fundamental to the overall efficiency of photosynthesis and the ability of plants to synthesize organic compounds from inorganic sources.