A lipid is found to have a sphingosine backbone and is covalently attached to a sugar unit. Which type of lipid is this, and what is its likely biological role?

• A. Glycerolipid; involved in energy storage.
• B. Sphingophospholipid; involved in nerve cell membrane structure.
• C. Sphingoglycolipid; involved in cellular recognition and signaling.
• D. Eicosanoid; involved in inflammation regulation.

Answer: (C)