1. Chapter 17 Lipids
17.6 Sphingolipids

2. Sphingosine Sphingosine is an 18-carbon unsaturated amino alcohol.

3. Ceramides In a ceramide,
the NH2 group in sphingosine is attached by an amide bond to a fatty acid

4. Sphingolipids Sphingolipids are similar to glycerophospholipids
contain sphingosine, a fatty acid, phosphate, and an amino alcohol

5. Sphingomyelin Sphingomyelin is a sphingolipid found in nerve cells
bonds the —OH of a ceramide to a phosphate ester of choline

6. Glycosphingolipids Glycosphingolipids are
sphingolipids that contain monosaccharides attached by a -glycosidic bond to the —OH group of ceramide

7. Cerebrosides Cerebrosides contain galactose or glucose attached by a
-glycosidic bond to the —OH group of ceramide
are found in the brain and the myelin sheath
are important in cellular recognition and tissue immunity

8. Gangliosides Gangliosides
are sphingolipids that contain chains of two to seven monosaccharides
are important in neurons
are found on cell membrane surfaces
act as receptors for hormones, viruses, and drugs
can cause genetic diseases if they accumulate

9. Gangliosides (continued)
GM2 is a ganglioside
that accumulates in Tay-Sachs disease when hexoamidase A is defective

10. Lipid Diseases (Lipidoses)
In many lipid diseases,
the deficiency of an enzyme causes the accumulation of glycolipids

11. Learning Check Identify each as a 1) fatty acid 2) triacylglycerol
3) amino alcohol 4) glycerophospholipid
5) glycosphingolipid
A. Glyceryl trioleate
B. Cephalin
C. Choline
D. Galactocerebroside
E. Palmitic acid

12. Solution Identify each as a 1) fatty acid 2) triacylglycerol
3) amino alcohol 4) glycerophospholipid
5) glycosphingolipid
A. Glyceryl trioleate 2) triacylglycerol
B. Cephalin 4) glycerophospholipid
C. Choline 3) amino alcohol
D. Galactocerebroside 5) glycosphingolipid
E. Palmitic acid 1) fatty acid