Video narration
If sunlight helps a plant make food, does sunlight itself become the sugar? Inside a leaf, photosynthesis happens in tiny cell parts called chloroplasts. This is where light powers two linked stages, not where sunlight turns into matter. First, light splits water brought into the leaf. Oxygen is released, and energy-carrying molecules are charged up for the next step. Here's the key: sunlight does not become sugar. It supplies the power. Those charged carriers deliver that energy to the second stage, where carbon dioxide from the air is joined into a small sugar building block. The leaf can use that block to make glucose and other sugars. So the carbon in sugar comes from the air, but the released oxygen comes from water. One leaf links them: it uses light to split water and build sugar from carbon dioxide, releasing oxygen along the way.