1. Lipid Metabolism I
Dr. Kevin Ahern

2. Fat and Glycerophospholipid Synthesis1 1 2 3 1 2 3 2 3
Fat and Glycerophospholipid Synthesis

3. Fat (Triacylglycerol)
Phosphatidic
Acid
Glycerol-3-P
Glycerophospholipids

5. Signaling
Catalysis
Fat Breakdown

6. Glycerophospholipids / Phosphatides

7. X

8. Glycerophospholipic Synthesis Involves CDP-Activated Intermediate
Two General Mechanisms
Phosphatidyl Portion
of Final Product
Will Split Off as CMP
+ PPi
CDP-Diacylglycerol
Phosphatidic Acid
+ CTP

9. CDP-Diacylglycerol + Inositol
+ CMP
Phosphatidylinositol
+ CMP
CDP-Diacylglycerol Inositol

10. CDP +
CMP

11. Phosphorylethanolamine
Second Mechanism - Activate Add-on Molecule
Adds to
Diacylglycerol
Splits Off
ATP
Phosphorylethanolamine
CTP
PPi
Ethanolamine
CDP-Ethanolamine

12. Phosphatidylethanolamine
CDP-Ethanolamine
+ CMP
+ Diacylglycerol

13. 1 1 2 2 3 3 1 3

14. Sphingolipid Biosynthesis
Amino Acid
Fatty Acid
Branch Point
Sphingolipids

15. Sphingolipid Synthesis
Ceramide Synthesis

16. Membrane Lipid Metabolism
Sphingolipids
Phosphocholine
R =
Sphingomyelin OR
Phosphoethanolamine
R =
Single Sugar
R =
Cerebroside
Complex Sugar
R =
Ganglioside

17. Sphingolipid Breakdown Diseases

18. Cholesterol Biosynthesis
Acetyl Group

19. Cholesterol Biosynthesis
Branch Point

20. IPP + DPP 30 Carbons 30 Carbons 15 Carbons 10 Carbons 5 Carbons Each
Lanosterol
30 Carbons
Squalene 2
15 Carbons
IPP + DPP
Farnesyl-PP
IPP
10 Carbons
Geranyl-PP
IPP
DMAPP
Acetyl-CoA
5 Carbons Each

21. Cholesterol
19 Steps
Lanosterol

22. Cholesterol Metabolism
Excretion
Cholesterol
Bile Acids
Mineralocorticoids
&
Corticosteroids

23. Cholesterol Metabolism

24. Lipid Movement From the Diet
Outside Intestine
Inside Intestine
Reattachment of
2 Fatty Acids
Removal of
2 Fatty Acids

25. Apolipoprotein Complexes

26. Chylomicron

28. Receptor-mediated Endocytosis

30. Foam Cell Aggregate

31. Carotid Artery Plaque