Believe it or not, plants need food too. Unlike you and me, however, plants make their own food - not in a kitchen but in their leaves. The process by which plants make their own food is called photosynthesis. Photosynthesis requires water, carbon dioxide, sunlight, and a special pigment called chlorophyll that only plants have. How does the plant get all these components?
Plants get carbon dioxide from the air around them through a part of their leaves called the stomata. The stomata are extremely small openings in leaves that open and close and allow the intake of carbon dioxide. At the same time, these stomata also allow transpiration, or the evaporation of water through leaves. This creates a transpiration pull, which is the suction force that draws the water up from the roots to leaves against the force of gravity. This brings us to how plants get water. Plants get the majority of their water through their roots. After the water is absorbed, it is transported up the xylem, a part of the plant’s stem, using the help of the previously mentioned transpiration pull and capillary action, which is attraction between water molecules and xylem cells. Finally, how does the plant get sunlight and chlorophyll? Chlorophyll naturally exists in most plants, and its main function is to allow the absorption of energy from sunlight. Now, the plant finally has all the resources to make its own food and undergo photosynthesis: water, carbon dioxide, sunlight, chlorophyll. How do all these components come together to make food?
Photosynthesis occurs in the chloroplasts, which are parts of the leaves’ cells that contain chlorophyll. When chlorophyll absorbs energy from the sunlight, photosynthesis begins. Next, the plant uses this energy from the sunlight to convert water from the roots and carbon dioxide brought through the stomata into sugar, also known as glucose, and oxygen. While the plant uses some sugar to finish photosynthesis and stores the rest of the sugars in their leaves to use later, the oxygen is released back into the plant’s surroundings through the stomata. Now the plant has made its own food and created oxygen that both humans and animals need to live!