Final answer:
The light-dependent reactions of photosynthesis occur in the thylakoid membranes of chloroplasts, where sunlight is converted into chemical energy.
Step-by-step explanation:
The site of light-dependent reactions for photosynthesis is the thylakoid membrane within chloroplasts. These reactions harvest energy from sunlight, and convert it into chemical energy in the form of ATP and NADPH. The energy-carrying molecules ATP and NADPH are then used in the Calvin cycle, which occurs in the stroma of the chloroplasts. The Calvin cycle uses the energy from these compounds to make G3P from CO₂. The thylakoid membranes contain photosystems that capture solar energy, which initiates the light-dependent reactions.