Which molecule is produced by photosynthesis and serves as a primary energy storage molecule?

• A. Oxygen
• B. Glucose
• C. Water
• D. Carbon dioxide

Answer: (B)

Photosynthesis captures light energy to build organic molecules from carbon dioxide and water, and the main product that stores energy is glucose. Its chemical bonds hold energy that cells can release later through cellular respiration to power activities. Plants also convert excess glucose into starch for storage, which is why glucose is described as a primary energy storage molecule. Oxygen is released as a byproduct of the light reactions, not used for storage. Water and carbon dioxide participate in the process as reactants or products, but they are not energy storage molecules.