Transcript 6. Sphingolipids

Chapter 17 Lipids
17.6
Sphingolipids
General, Organic, and Biological Chemistry
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Sphingosine
Sphingosine is an 18-carbon unsaturated amino alcohol.
Sphingosine
General, Organic, and Biological Chemistry
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Ceramides
In a ceramide,
 the NH2 group in
sphingosine is
attached by an amide
bond to a fatty acid
General, Organic, and Biological Chemistry
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Sphingolipids
Sphingolipids
 are similar to glycerophospholipids
 contain sphingosine, a fatty acid, phosphate, and an
amino alcohol
General, Organic, and Biological Chemistry
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Sphingomyelin
Sphingomyelin
 is a sphingolipid found in nerve cells
 bonds the —OH of a ceramide to a phosphate ester of
choline
General, Organic, and Biological Chemistry
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Glycosphingolipids
Glycosphingolipids are
 sphingolipids that contain monosaccharides attached
by a -glycosidic bond to the —OH group of ceramide
General, Organic, and Biological Chemistry
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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
General, Organic, and Biological Chemistry
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Gangliosides
Ganglia: Nerve tussues at CNS/PNS
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
General, Organic, and Biological Chemistry
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Gangliosides (continued)
GM2 is a ganglioside
 that accumulates in Tay-Sachs disease when
hexoamidase A is defective
General, Organic, and Biological Chemistry
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Lipid Diseases (Lipidoses)
In many lipid diseases,
 the deficiency of an enzyme causes
the accumulation of glycolipids
General, Organic, and Biological Chemistry
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Learning Check
Identify each as a
1) fatty acid
3) amino alcohol
5) glycosphingolipid
A.
B.
C.
D.
E.
2) triacylglycerol
4) glycerophospholipid
Glyceryl trioleate
Cephalin
Choline
Galactocerebroside
Palmitic acid
General, Organic, and Biological Chemistry
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Solution
Identify each as a
1) fatty acid
3) amino alcohol
5) glycosphingolipid
2) triacylglycerol
4) glycerophospholipid
A.
B.
C.
D.
E.
2)
4)
3)
5)
1)
Glyceryl trioleate
Cephalin
Choline
Galactocerebroside
Palmitic acid
General, Organic, and Biological Chemistry
triacylglycerol
glycerophospholipid
amino alcohol
glycosphingolipid
fatty acid
Copyright © 2010 Pearson Education, Inc.
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