Carbohydrates play many vital biological roles in different organisms:

Primary source of energy: The primary biological role of carbohydrates is energy production. Glucose, a simple sugar, is crucial for the synthesis of ATP, which is the main source of energy for cells.

Energy Storage: Excess glucose is stored as starch in plants and glycogen in animals and used for future energy needs.

Cell Communication: Glycolipids and glycoproteins that are present on cell surfaces play a critical role in cell recognition and signaling.

Genetic Information: Ribose is a key sugar in RNA and deoxyribose is a key sugar DNA. 

Immune Function: Carbohydrates on the surfaces of pathogens are involved in initiating immune responses.

Digestive Health: Dietary fibers in carbohydrates support digestion and gut health.

Structural Support: Cellulose in plant cell walls and chitin in fungi and arthropods contribute to structural stability.