The roles of sugars include providing energy, constituting organisms, providing carbon skeletons, and serving as information molecules for cellular recognition. 1. Provide energy: Sugars are the main source of energy for life activities, such as starch in plants and glycogen in animals. 2. Constitute organisms: Sugars are structural components of organisms, such as cellulose in plant cell walls. 3. Provide carbon skeleton: Sugars are important intermediate metabolites, providing carbon skeleton for synthesizing other molecules such as amino acids, nucleotides, fatty acids etc. 4. As information molecules for cell recognition: Sugars can be used as information molecules for cell recognition, such as the sugar chains of glycoproteins are the basis of blood type substances, which are closely related to cell recognition, metabolic regulation, development, cancer, aging and so on. For more information about sugars, please consult your doctor or dietitian.