1. Complex Lipids

2. Vignette 3
Introduction: A 3 week premature baby boy born to a diabetic mother by cesarean section.
Presenting complaints: Bluish discoloration of the skin and mucus membranes (cyanosis) with apnea.
Examination: Unusual breathing movement -- drawing back of chest muscles with breathing. APGAR score less than 5
Investigations: lecithin/sphingomyelin ratio of amniotic fluid at 34th week of gestation = 1.2
Laboratory investigations: Blood gas analysis of baby indicates low oxygen and excess acid in the body fluids. Blood culture negative for infection.
Diagnosis: Acute respiratory distress syndrome (ARDS)/ Infant respiratory distress syndrome (IRDS)

3. Classification - (Structure)
LIPIDS
SIMPLE
LIPIDS
COMPLEX
LIPIDS
Fats and
Oils
Waxes
Phospholipids
Glycolipids
Glycero-
phospho-
lipids
Sphingo-
phospho
lipids
Cerebro-
sides
Globo-
sides
Ganglio-
sides
Sulfa-tides

4. Simple Lipids
FATTY ACID
FATTY ACID
FATTY ACID
Triacylglyceride

5. Complex lipids: phospholipids Glycerophospholipids Ether Glycerolipids
FATTY ACID
FATTY ACID
FATTY ACID P P
HEAD GROUP
HEAD GROUP

6. Complex lipids: Phospholipids
Glycerophospholipids
Ether Glycerolipids
Sphingophospholipids

7. Sphingophospholipids
Complex lipids:
Sphingophospholipids O
SINE
FATTY ACID P
HEAD GROUP

8. Glycerophospholipids

9. Phosphatidic acid
FATTY ACID
FATTY ACID P

10. Glycerophospholipids

13. (16:0, 18:0)
(18:1, 18:2, 18:3)

14. Phosphatidylcholine
Lung surfactant = 90% lipids (Dipalmitoylphosphatidyl-choline, DPCC; Dipalmitoylecithin) + 10% protein

15. Cardiolipin Diphosphatidylglycerol Distribution:
Inner mitochondrial membrane
Function:
Maintenance of respiratory complexes

16. Ether Glycerolipids

17. Plasmalogens Distribution: Function:
Phosphatidalethanolamine (in nerve tissue)
Phosphatidalcholine (in heart muscle)
Function:
More resistant to oxidative stress therefore provides protection to tissues with active aerobic metabolism

18. Platelet-activating factor
Distribution
Released by a variety of cell types, including platelets, neutrophils, basophils, and endothelial cells.
Functions
PAF activates inflammatory cells and mediates hypersensitivity, acute inflammatory, and anaphylactic reactions.

19. Phosphatidylinositol (PI)
Distribution
present in all tissues and cell types. Especially abundant in brain tissue, (10% of the phospholipids).
Functions:
Cell signaling,
Reservoir of arachidonic acid
Protein anchoring
Stearic acid (18:0)
Arachidonic acid (20:4)

20. Phosphatidylinositol 4, 5 –bisphosphate (PIP2)

22. Protein anchoring

23. Sphingophospholipids

24. Sphingophospholipids

25. Sphingosine 2-amino-4-octadecene-1,3-diol
C-18 alcohol containing two –OH groups, one amino group and one double bond

26. Sphingomyelin Distribution
Constituent of the myelin sheath of nerve fibers.
Functions
Building block of myelin sheath
Primary source of ceramide
Signal transduction

27. Phospholipids - Degradation

28. Niemann-Pick disease autosomal recessive disease
inability to degrade sphingomyelin.
deficiency of sphingomyelinase - a type of phospholipase C.

29. Glycolipids/glycosphingolipids

30. Glycolipids/glycosphingolipids
SINE
FATTY ACID
CARBOHYDRATE

31. Glycolipids/glycosphingolipids
Distribution
essential components of all membranes in the body. greatest amounts in nerve tissue
Functions
regulation of cellular interactions, growth, and development
Blood group antigens
CEREBROSIDES
GLOBOSIDES
GANGLIOSIDES
SULFATIDES

32. Cerebrosides
ceramide monosaccharides -simplest neutral glycosphingolipids
Galactocerebroside - the most common cerebroside found in membranes
Glucocerebroside - serves primarily as an intermediate in the synthesis and degradation of the more complex glycosphingolipids.
cerebrosides are found predominantly in the brain and peripheral nervous tissue, with high concentrations in the myelin sheath

33. Galactocerebroside

34. Globosides Ceramide oligosaccharides
Addition of monosaccharides (including GalNAc) to a glucocerebroside
e.g.
Cer-Glc-Gal (lactosylceramide)
Cer-Glc-Gal-Gal-GalNac-GalNac (Forssman antigen)

35. Gangliosides Negatively charged at physiological pH
Glycolipids containing sialic acid (N-acetylneuraminic acid, NANA)
found primarily in the ganglion cells of the central nervous system, particularly at the nerve endings

36. Gangliosides Nomenclature
is based on the number of sialic acid residues
'GM' a single (mono) sialic acid,
GD, GT and GQ two, three and four sialic acid residues in the molecule, respectively
on the sequence of the carbohydrates.
The number after the GM, e.g. GM1 refers to the structure of the oligosaccharide.
These numbers were derived from the relative mobility of the glycolipids on thin layer chromatograms; the larger, GM1, gangliosides migrate the most slowly.

37. Sulfatides cerebrosides that contain sulfated galactosyl residues
negatively charged at physiologic pH
found predominantly in nerve tissue and kidney

38. Sphingolipidosis
Defects in sequential degradation of glycolipids lead to a number of lysosomal storage diseases, Sphingolipidosis (cerebrosidoses and gangliosidoses)
A specific lysosomal hydrolytic enzyme is deficient in each disorder. Therefore, usually only a single sphingolipid (the substrate for the deficient enzyme) accumulates in the involved organs in each disease

40. THE END!