How do plants convert sunlight into usable food energy?

Plants convert sunlight into food through photosynthesis, which occurs primarily in the chloroplasts of leaf cells. Chlorophyll and other pigments absorb light energy, mainly from red and blue wavelengths. This energy powers two main stages: the light-dependent reactions in the thylakoid membranes, where water molecules are split and energy is captured as ATP and NADPH, and the Calvin cycle in the stroma, where that stored energy is used to convert carbon dioxide from the air into glucose. The plant then uses this glucose as a direct energy source through cellular respiration or converts it into starch, cellulose, and other compounds needed for growth and maintenance.