Plants don’t eat the way we do. Instead of heading to a grocery store, plants make their own food with sunlight. The complex process of turning sunlight into food energy is called photosynthesis.
Photosynthesis allows plants to make food for themselves by converting light energy into chemical energy. Plants turn carbon dioxide and water into glucose, an energy-filled food, also known as sugar. Just as sugar gives us energy, it is food for the plant.
Plants store sugar in a variety of ways. The onion plant, for example, can store sugar in the onion bulb, which is made out of swollen leaves. When the bulb gets overheated by cooking, the sugar in the onion plant turns brown or caramelizes.
Every plant needs sunlight to survive. Some plants like the potato plant can survive without sunlight for a period of time. The potato plant can live for six months without the energy of the sun, because it survives on its stored chemical energy in the form of starch in tubes, or small sacks called tubers.
After three weeks back in daylight, the potato plant begins growing again and its leaves turn green due to chlorophyll. Chlorophyll, a green pigment in leaves, harnesses energy from sunlight that falls directly on the plant. The potato plant can now collect enough sunlight energy to build another tuber and replace the old tuber. If the potato plant was planted in the ground, the energy gathered by its own leaves will be stored in the new potato tuber, and the old potato tuber will die off.
Plants might seem mysterious, but just like humans, they all need food to survive. Luckily, they can make it themselves.