What are carbohydrates?

People, wanting to know what are carbohydrates, must bear in mind that carbohydrates are the main source of energy. Carbohydrates are represented by starches found in grains, legumes, and tubers as well as by sugars in plants and fruits. The living cells use carbohydrates in the form of glucose. After absorption from the intestine, glucose gets into the liver and is stored there as glycogen. Another portion of glucose passes into the bloodstream and is carried to the muscles and organs. Carbohydrates are burned during metabolic processes producing energy, carbon dioxide and water. Foods with high carbohydrate content are often the cheapest and richest in energy.