1. GLYCOLIPIDS .

2. Why should I care?
Your brain is like a computer with one REALLY big difference. You can back up all the information on your computer and if it crashes you can restore all the information. Well we DO NOT have a restore button. Once the neurons in our brains that held a particular memory or knew how to speak are gone we can’t get them back. There is no restore button. So treat your brain well, you only get one.
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3. Glycolipids
Glycolipids are derivatives of ceramides with carbohydrate directly attached to ceramide
In contrast to sphingomyelin they do not have a phosphocholine group .

5. Glycolipids
Are essential components of cell plasma membranes (outer leaflet), but are most abundant in nervous tissues
Outside
Inside

6. Glycolipid structure — cerebrosides
The carbohydrate component is linked by an O-glycosidic bond to ceramide
Cerebrosides contain a single sugar (Glu or Gal) or few sugars; they are abundant in brain and myeline sheath

7. Glycolipid structure — gangliosides
Gangliosides are acidic glycosphingolipids
They contain oligosaccharides with terminal, charged N-acetyl neuraminic acids (NANA)
Depending on the number of NANA sugars, gangliosides are designated M, D, T, Q (e.g., GM)
Ganglioside GM2

8. Roles of glycolipids
Glycolipids have important roles in cell interactions, growth, and development
They are very antigenic (e.g., blood group antigens);
act as surface receptors for some toxins and viruses;
and undergo major changes during cell transformation

9. Glucosyl-ceramide / Glucocerebroside
Monohexoside
Glu
Ceramide
Dihexoside
Gal
Glu
Ceramide
Trihexoside
Gal
Gal
Glu
Ceramide
Biosynthesis of membrane lipids and steroids 1

10. Galactosyl – ceramide / Galactocerebroside
Monohexoside
Gal
Ceramid
Dihexozid
Gal
Gal
Ceramid
Biosynthesis of membrane lipids and steroids 1

11. Biosynthesis of membrane lipids and steroids 1
ABO blood group system
Glu
Gal
GalNAc
Gal
„O” (H) antigen
Fuc
Glu
Gal
GalNAc
Gal
GalNAc
„A” antigen
Fuc
Glu
Gal
GalNAc
Gal
Gal
„B” antigen
Fuc
Biosynthesis of membrane lipids and steroids 1

12. GLYCOSPHINGOLIPIDS AS DETERMINANTS OF BLOOD GROUPS
The human blood groups (O, A, B) are determined in part by the oligosaccharide head groups of these glycosphingolipids.
Glc:D-glucose
Gal:D-galactose
GalNAc:N-acetyl-D-galactosamine
Fuc:fucose

15. Glycolipid degradation
Degradation of glycosphingolipids occurs in lysosomes after endocytosis of membrane portions
A series of acid hydrolases participate in the degradation
Degradation is sequential in the order: last on, first off

16. Glycolipid degradation
Sphingolipidoses result from deficiencies of specific degradative enzymes
They are diagnosed by accumulation of specific sphingolipid, enzyme activity measurements, and histologic examination of affected tissue

17. Biosynthesis of membrane lipids and steroids 1
Gaucher’s - disease
Accumulation of glucocerebrosides in reticuloendothelial cells of spleen, liver, and bone marrow
the most common of lysosomal storage disease
Mental retardation /
Glu
Gaucher
Ceramid
b-glukozidáz
Biosynthesis of membrane lipids and steroids 1

18. Biosynthesis of membrane lipids and steroids 1
Krabbe disease
Accumulation of Galactosyl ceramide .
Gal
Ceramid
b-galaktosidase
Biosynthesis of membrane lipids and steroids 1

19. THANKS