Carbohydrates Definition and Properties

Definition and Composition of Carbohydrates

• Carbohydrates are chemically defined as aldehyde or ketone derivatives of polyhydroxy alcohols or compounds that yield these derivatives on hydrolysis.
• Composed of the elements carbon (C), hydrogen (H), and oxygen (O).
• Also known as saccharides, meaning "sugars".

Production and Functions of Carbohydrates

• Produced by photosynthesis in plants, where glucose is synthesized from CO2, H2O, and energy from the sun.
• Oxidized in living cells (respiration) to produce CO2, H2O, and energy.
• Functions:
  • Source of energy for living beings (e.g., glucose).
  • Storage form of energy (e.g., glycogen in animal tissue and starch in plants).
  • Serve as structural components (e.g., glycosaminoglycans in humans, cellulose in plants, and chitin in insects).
  • Non-digestible carbohydrates like cellulose serve as dietary fibers.
  • Constituents of nucleic acids RNA and DNA (e.g., ribose and deoxyribose sugar).
  • Play roles in lubrication, cellular intercommunication, and immunity.
  • Involved in detoxification (e.g., glucuronic acid).