2. Fatty acids metabolism 1.Definition. 2.Function of F.A. 3.Classification of F.A. 4.Biosynthesis of F.A.

3. 2. Function of F.A. 1.It enters in the structure of cell membrane. 2.It enters in the formation of TAGs, phospholipids, CE., glycolipids,…etc. 3.Arachidonic acid is the precursor of PGs. 4.Stored FA in the form of TAGs serves as the major energy reserve of the body

4. 3. Classification of F.A. F.As may be classified according to: 1.Length: short & long chain. 2.Bonds: saturated & unsaturated. 3.Biological importance: essential & non essential. 4.Carriers: bound & unbound to albumin.

8. 4. F.A Synthesis 1.Translocation of acetyl COA. 2. Structure of FAS. 3. Types of FA synthesis. A. Extra-mitochondrial (cytoplasmic or de novo) biosynthesis. B. Microsomal biosynthesis. C. Mitochondrial biosynthesis. 4. Regulation of FA synthesis.

14. FAS enzyme monomer

16. A. Extra-mitochondrial (cytoplasmic or de novo) biosynthesis.

17. Step:1

18. Step:2

19. Step:3

20. Step:4

21. Step:5

22. Step:6

23. Step:7

25. H2O

27. Step:1

28. Step:2

30. B. Microsomal biosynthesis.

40. C. Mitochondrial biosynthesis.

42. Differences between fatty acid biosynthesis MicrosomalMitochondrialExtra-mitochondrialPoints MicrosomalMitochondrialCytoplasmicSites NADPH Coenzymes Malonyl CoAAcetyl CoAMalonyl CoABuilding unit CoASH ACPThe carrier Separate enzymes Multi-enzyme complexEnzymes Elongation of moderate chain FA(C10 C24) Elongation of moderate chain FA(C10 C20) De novo biosyn-thesis of FAFunctions

43. 1.Hormonal regulation. 2.Feed back regulation. 3.Diet regulation

51. Step:1

52. Step:2

53. Step:3

54. Step:4