What role do carbohydrates play in living organisms?

Carbohydrates are vital biomolecules that serve multiple essential functions in living organisms, primarily acting as structural components and energy sources. In terms of energy, carbohydrates, such as glucose, are key molecules that organisms utilize during cellular respiration to produce ATP, the primary energy currency of cells. Additionally, carbohydrates can be stored in the form of glycogen in animals and starch in plants, providing a readily accessible source of energy when needed.

Beyond their role in energy metabolism, carbohydrates also contribute significantly to structural integrity. For example, in plants, cellulose, a complex carbohydrate, forms the cell wall, providing rigidity and protection. Chitin serves a similar structural role in the exoskeletons of arthropods and the cell walls of fungi. The combination of these functions underscores why carbohydrates are regarded as fundamental components in living organisms.