Head groups sphingolipids

Figure 22.6 Sphingolipids are constructed of sphingosine derivatives containing an acylated fatty acid and a head group attached to the hydroxyl.

Figure 22.7 Common sphingolipid derivatives include small and highly complex head groups.

Acetyl coenzyme A is the precursor of both cholesterol and fatty acids 39 Phosphatidic acid is the precursor of all glycerolipids 42 Sphingolipids are biosynthesized by adding head groups to the ceramide moiety 44... 

Gangliosides, the most complex sphingolipids, have oligosaccharides as their polar head groups and one or more residues of Ai-acetylneuraminic acid (Neu5Ac), a sialic acid (often simply called sialic acid ), at the... 

FIGURE 21-31 Biosynthesis of sphingolipids. Condensation of palmitoyl-CoA and serine followed by reduction with NADPH yields sphinganine, which is then acylated to N-acylsphinganine (a ceramide). In animals, a double bond (shaded pink) is created by a mixed-function oxidase, before the final addition of a head group phosphatidylcholine, to form sphingomyelin glucose, to form a cerebroside. 

Synthesis of plasmalogens involves formation of their characteristic double bond by a mixed-function oxidase. The head groups of sphingolipids are attached by unique mechanisms. 

The answer is c. (Murray, pp 230-267. Scriver, pp 2297-2326. Sack, pp 121-138. Wilson, pp 287-320.) Ceramide is the basic unit composing all sphingolipids, which include sphingomyelin and gangliosides. Sphingomyelin, which usually contains phosphocholine as a polar head group, is... 

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