Lesson 6 : Carbohydrates - Classification- Structure, Function


Energy-storage molecules (i.e. glycogen, starch). Carbohydrates serve as energy storage and transport , fuels, and metabolic intermediates (starch, glycogen ). The primary function of carbohydrates is to provide energy (ATP) to drive metabolic processes for the body, especially the brain and the nervous system and developing red bloods cells. This energy is needed to carry on body processes such as breathing, maintaining body temperature, and contraction and relaxation of the heart and muscles. An enzyme called amylase helps break down carbohydrates into glucose (blood sugar), which is used for energy by the body.

Structural - cell walls and exoskeletons of some organisms are formed of carbohydrates (e.g., cellulose in plants and chitin in animals). Polysaccharides are structural elements in the cell walls of bacteria and plants. In fact, cellulose, the main constituent of plant cell walls, is one of the most abundant organic compounds in the biosphere

In addition, carbohydrates and their derivatives play major roles in the working process of the immune system, fertilization, pathogenesis, blood clotting, and development. Carbohydrate derivatives found in coenzymes (FAD) and nucleic acids. Ribose and deoxyribose sugars form part of the structural framework of RNA and DNA..

Carbohydrates are linked to many proteins and lipids, where they play key roles in mediating interactions between cells and other elements in the cellular environment.

Glucose is the main carbohydrate that the body breaks down for energy. The major pathway by which glucose is broken down for energy requires oxygen, and the final products are carbon dioxide, water, and energy. In the muscles, if oxygen is in short supply, some glucose can be broken down for energy by a different pathway that does not require oxygen; however, the final products are lactic acid and energy. Lactic acid builds up in the muscles and causes cramping.

Last modified: Tuesday, 17 January 2012, 11:22 AM