What is a possible product formed from carbon dioxide during photosynthesis?

• A. Protein
• B. Lipid
• C. Carbohydrate
• D. Nucleic acid

Answer: (C)

Photosynthesis fixes carbon dioxide into organic molecules in the Calvin cycle, using energy from ATP and reducing power from NADPH produced in the light reactions. The immediate product is a three-carbon sugar that can be built into carbohydrates such as glucose and then stored as starch or transported as sucrose. Carbohydrates are the direct products formed from CO2 during this process. Proteins, lipids, and nucleic acids involve other nutrients (like nitrogen and phosphorus) and additional steps beyond the initial carbon fixation, so they’re not the immediate products formed from CO2 in photosynthesis.