Question

In Glycolipids and sphingolipids, glycerol is replaced by which amino alcohol?

• A. Sphingomyelins
• B. Gangliosides
• C. Sphingosine
• D. Sulfatides

Hint:

The name of the class of lipids often gives a clue to its structure. Just as \textbf{glycero}lipids have a \textbf{glycerol} backbone, \textbf{sphingo}lipids have a \textbf{sphingosine} backbone. The other options are examples of complex sphingolipids, not the fundamental building block.

Answer 1

The Correct Option is C

Step 1: Concept Summary:
Biological membranes contain lipids, categorized as glycerophospholipids (glycerol backbone) or sphingolipids. This question identifies the sphingolipid backbone, which substitutes for glycerol.

Step 2: Explanation:
- Sphingosine, an 18-carbon amino alcohol with an unsaturated hydrocarbon chain, constitutes the sphingolipid backbone.
- A sphingolipid results from a fatty acid binding to sphingosine via an amide linkage, forming ceramide. Head groups attach to ceramide.
- Incorrect options are complex sphingolipids, not the backbone:
- Sphingomyelins: ceramides with a phosphocholine or phosphoethanolamine head group.
- Gangliosides and Sulfatides: glycolipids (glycosphingolipids) with a complex oligosaccharide head group.

Step 3: Conclusion:
Sphingolipids utilize sphingosine, not glycerol, as their backbone. Thus, option (C) is correct.