Plants need sunlight to change water and carbon dioxide into a form that they can use. This process, called photosynthesis, uses chlorophyll from the plant's leaves to produce carbohydrates and oxygen. Initially, the type of carbohydrate that photosynthesis produces in plants is glucose. Once the plant has captured the energy from the sun to break down carbon dioxide and water into glucose, it is then used as an essential part of the plant's metabolism. Plant proteins, enzymes and even its genetic make-up are all produced thanks to glucose. Plant glucose is also changed into fats and complex carbohydrates, which are starches.
Plants use glucose in much the same way that humans do, specifically, as energy to carry out everyday functions. Glucose helps plants to have strong cell walls and tissues. The plant uses part of its glucose supply to form fiber, or cellulose. Besides giving the plant structure in the stems and leaves, plant cellulose provides humans and animals with an important source of dietary fiber. Plants also transform glucose into starches and fats. For example, in potatoes, glucose becomes a complex carbohydrate, or a starch. Starch is also found in wheat or rice, and in all whole grains. Plants use glucose to become starch in their seeds. Later, this starch forms an important source of energy during germination.
Plants need sunlight to successfully carry out photosynthesis. Leaves that have direct exposure to the sun for many hours produce glucose faster than leaves that are in the shade. The green color you observe in plant leaves is actually chlorophyll, which is the other key component in photosynthesis. Thanks to this process, plants are able to produce their own source of energy, glucose. Humans benefit from photosynthesis as well. Besides oxygen production, plants' transformation of glucose into complex carbohydrates such as starch and cellulose contribute toward a healthy diet.