Video narration
That houseplant on your sunny windowsill-does it really get its food from the soil? Look closely at its leaves. Water travels up from the roots, while carbon dioxide, a gas in the air, enters the leaves. Soil isn't the plant's food. The leaves make it. Photosynthesis is the process in which a leaf uses light energy to make sugar from water and carbon dioxide. Inside each leaf, chlorophyll, the green pigment, captures sunlight and powers this food-making. The light supplies energy; it doesn't become the sugar. As sugar forms, oxygen is released into the air. The plant uses sugar for energy and growth. At the windowsill, you can think of the leaf as a tiny food-maker, taking in water and air while sunlight powers its work. No: sunlight powers the leaves to make sugar from water and carbon dioxide, releasing oxygen.