What are the light-independent reactions?

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Multiple Choice

What are the light-independent reactions?

Light-independent reactions are the Calvin Cycle, a series of carbon-fixation and sugar-building steps inside the chloroplast stroma that use energy-rich molecules made during the light reactions. They rely on ATP and NADPH produced by those light-driven processes to convert carbon dioxide into sugar precursors. In the cycle, CO2 is fixed by Rubisco to a five-carbon sugar to form 3-phosphoglycerate, which is then reduced and phosphorylated using ATP and NADPH to produce glyceraldehyde-3-phosphate. Most of the G3P is recycled to regenerate RuBP, while some exits the cycle to become glucose and other carbohydrates. This pathway does not require light directly, only the energy carriers generated by light reactions. The other options refer to processes tied to capturing light and generating energy (light-dependent reactions and photophosphorylation) or to a separate metabolic pathway (glycolysis) that occurs outside photosynthesis.

Light-independent reactions are the Calvin Cycle, a series of carbon-fixation and sugar-building steps inside the chloroplast stroma that use energy-rich molecules made during the light reactions. They rely on ATP and NADPH produced by those light-driven processes to convert carbon dioxide into sugar precursors. In the cycle, CO2 is fixed by Rubisco to a five-carbon sugar to form 3-phosphoglycerate, which is then reduced and phosphorylated using ATP and NADPH to produce glyceraldehyde-3-phosphate. Most of the G3P is recycled to regenerate RuBP, while some exits the cycle to become glucose and other carbohydrates. This pathway does not require light directly, only the energy carriers generated by light reactions.

The other options refer to processes tied to capturing light and generating energy (light-dependent reactions and photophosphorylation) or to a separate metabolic pathway (glycolysis) that occurs outside photosynthesis.

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