Plants and other photosynthetic organisms get their energy directly from the sun by absorbing the light and using it to create energy-rich carbohydrates such as glucose. During the process of photosynthesis plants take in light energy from the air, and water through their roots to produce sugar and oxygen. Carbohydrates are organic macromolecules that are made up of carbon, hydrogen, and oxygen atoms and are used for energy storage or as structural molecules.