Final answer:
Carbohydrates are found on the exterior surface of the cell membrane and aid in cell recognition and identification.
Step-by-step explanation:
Carbohydrates are found on the exterior surface of the cell membrane and are bound either to proteins (forming glycoproteins) or to lipids (forming glycolipids). These carbohydrate chains, along with peripheral proteins, form specialized sites on the cell surface that allow cells to recognize each other. This recognition function is important for the immune system to differentiate between body cells and foreign cells.