What is a characteristic feature of sphingolipids?

Sphingolipids are characterized by having a long-chain fatty acid as part of their structure, with sphingosine serving as their backbone. Sphingosine is an amino alcohol that contributes to the unique features of sphingolipids compared to other classes of lipids, such as glycerolipids. The long-chain nature of the fatty acids often provides these molecules with specific properties related to membrane fluidity and stability.

In contrast, sphingolipids do not typically contain glycerol as a backbone, as this would classify them as glycerolipids instead. They can also include carbohydrate moieties, but not all sphingolipids are carbohydrate-rich, which makes that feature less definitive. Finally, while some sphingolipids may have a phosphate group (particularly sphingomyelin), not all sphingolipids possess this characteristic, so it cannot be considered a universal feature of this class of lipids.