Carbohydrates

Saccharides, or sugars, constitute a large group of organic compounds primarily made up of oxygen, hydrogen, and carbon. The simple saccharides—that is, the monosaccharides and disaccharides—are sweet and include the common sugars such as glucose, fructose, galactose, sucrose, lactose, and maltose. Starch, cellulose, and glycogen are well-known plant polysaccharides. Seaweeds contain polysaccharides, such as agar, alginate, and carrageenan. Carbohydrates are formed in plants and seaweeds by photosynthesis, a process in which carbon dioxide and water combine, releasing oxygen.