What does the carbon fixation reaction convert?

What does the carbon fixation reaction convert?

• A. Inorganic carbon (CO2) into an organic acid.
• B. Organic carbon into inorganic carbon.
• C. Glucose into starch.
• D. Water into oxygen.

Answer: (A)

Carbon fixation refers to turning inorganic carbon dioxide into organic carbon compounds that the plant can use. In the Calvin cycle, CO2 is combined with a five-carbon sugar to form a new carbon skeleton that is eventually converted into sugars like glucose. This is the step that builds organic carbon from inorganic carbon, enabling storage and growth. The other ideas describe different processes: converting organic carbon back into inorganic carbon happens in respiration/decomposition; making starch from glucose is storing energy from already-made sugars; and splitting water to release oxygen occurs in the light-dependent reactions, not carbon fixation.

Carbon fixation refers to turning inorganic carbon dioxide into organic carbon compounds that the plant can use. In the Calvin cycle, CO2 is combined with a five-carbon sugar to form a new carbon skeleton that is eventually converted into sugars like glucose. This is the step that builds organic carbon from inorganic carbon, enabling storage and growth.

The other ideas describe different processes: converting organic carbon back into inorganic carbon happens in respiration/decomposition; making starch from glucose is storing energy from already-made sugars; and splitting water to release oxygen occurs in the light-dependent reactions, not carbon fixation.