How Do Plants Make Their Own Food?

Imagine you forgot to eat all day. You would feel tired and hungry very quickly! Now think about a plant. A plant has no mouth, no lunch box, and it never visits a shop. Yet plants grow, make seeds, and live for years — sometimes hundreds of years. How do they do it? Where does their food come from? Think about it for a moment before we find out.

Plants make their own food using a process called photosynthesis. The word comes from Greek: 'photo' means light and 'synthesis' means putting things together. So photosynthesis means 'putting things together using light'. Photosynthesis happens mainly inside the leaves of a plant. Leaves are green because they contain a special substance called chlorophyll. Chlorophyll is what captures energy from sunlight. To make food, a plant needs three ingredients: 1. Sunlight — captured by chlorophyll in the leaves. 2. Water — absorbed through the roots from the soil. 3. Carbon dioxide — a gas that the plant takes in through tiny holes in its leaves called stomata. The plant uses the energy from sunlight to turn water and carbon dioxide into glucose. Glucose is a type of sugar that gives the plant energy to grow, flower, and produce seeds. During photosynthesis, the plant also releases oxygen into the air. Oxygen is the gas that you and every other animal breathes in to stay alive. This means that every time a plant photosynthesises, it is helping you breathe! Here is a simple way to remember the process: Water + Carbon dioxide + Sunlight → Glucose + Oxygen You can observe photosynthesis yourself. On a sunny day, put a leaf in a glass of water in bright sunlight. After a while, you may see tiny bubbles forming on the leaf — those bubbles are oxygen being released!