How can a plant make food out of sunlight?

Think of a sunny windowsill with a small plant in a pot. Maybe you have felt that same warm sun on your own cheeks. The plant never eats a single crumb, yet it keeps growing taller.

You eat breakfast and dinner to grow, but a plant has no mouth and no plate. So how can a plant make its own food out of sunlight?

The food making starts in the leaves. Each flat green leaf spreads out wide, like an open hand, to catch as much sunlight as it can. A wide leaf catches far more light than a thin twig could.

Inside every leaf is green stuff called chlorophyll, which means the green helper that catches sunlight. Chlorophyll is what makes leaves look green. It grabs the energy in the sunlight and holds on to it, so the leaf can use that energy for work.

Sunlight alone cannot become food, so the plant needs water too. Its roots drink water from the soil, and the stem carries it up to the leaves, like juice rising through a straw. Now the leaf has sunlight and water. Can you guess what else it takes in, something all around you that you cannot see?

It is the air! Leaves have tiny holes, far too small for your eyes, and they take in a gas from the air. People and animals breathe out this very gas, and the leaf needs it as one more building piece for food.

Now the chlorophyll gets to work. It uses the energy from the sunlight to join the water and that gas from the air together. Out of them, the leaf makes sugar, a sweet food made right inside the leaf.

This sugar is the plant's food. The plant carries it to every part, from its roots to its newest buds. With that food, the plant has the energy to grow new leaves, stems and flowers.

One word to remember: chlorophyll. Sunlight lands on a leaf, and the chlorophyll inside uses its energy to turn water and air into sugar, the plant's own food.

Sleep well, little leaf watcher, and the next time you see a green leaf in the sunshine, you can smile and know it is quietly cooking its lunch.