Which energy transformation is primarily associated with chloroplasts?

• A. Conversion of chemical energy to gravitational potential energy
• B. Production of ATP during cellular respiration
• C. Capture of light energy to synthesize glucose
• D. Breakdown of proteins for energy

Answer: (C)

Chloroplasts are where photosynthesis happens, so the energy transformation most tied to them is turning light energy into chemical energy stored in glucose. In the light-dependent reactions, light energy is captured by chlorophyll and converted into ATP and NADPH. Those molecules then power the Calvin cycle, which fixes carbon dioxide into glucose, effectively storing the captured energy in chemical bonds. That's why this option is the best fit: it directly describes light energy being converted into stored chemical energy within sugars. The other ideas involve energy changes that occur in different contexts—mitochondria during respiration, general cellular energy metabolism, or energy changes unrelated to chloroplasts—so they’re not the primary association here.