1. LIPID SYNTHESIS

2. Fatty acids are built from 2-C units exported from the mitochondria as citrate:
citrate ® OAA + acetyl-CoA
This occurs in high-energy conditions, when isocitrate dehydrogenase is
inhibited by NADH, ATP.
The OAA is reduced to malate and recycled into the mitochondria.

4. (enzyme-biotin-CO2 intermediate)

8. O ||
R-CH2-CH2-CH2-C-S-ACP
malonyl-S-ACP
NADP+ O ||
R-CH2-C-S-ACP ﾟ
CO2
HS-ACP
NADPH
O O
|| ||
R-CH2-C- CH2-C-S-ACP ﾟ
H O
| ||
R-CH2-C=C-C-S-ACP | H
NADPH
H2 O
NADP+
OH O
| ||
R-CH2-C- CH2-C-S-ACP | H

12. R-C(=O)-ACP or R-C(=O)-CoA
ACP or CoA
1-acyl-glycerol-3-P
triacylglycerol
CoA Pi
phosphatidyl-choline or -ethanolamine
CDP-choline or CDP-ethanolamine
CMP
Phosphatidic acid
Glycerol-3-P
R-C(=O)-CoA

13. Control of FA synthesis in the cytoplasm occurs at acetyl-CoA carboxylase

14. Summary
Fatty acids are synthesized in the cytoplasm, using acetyl-CoA
exported from mitochondria (as citrate).
The synthesis of fatty acids follows a “ß-reduction” cycle.
Fatty acids are combined with glycerol-3-P to form triglycerides
and phospholipids.

15. R-C(=O)-ACP or R-C(=O)-CoA
ACP or CoA
Glycerol-3-P
1-acyl-glycerol-3-P
R-C(=O)-ACP or R-C(=O)-CoA
H2O
ACP or CoA
Phosphatidic acid Pi
R-C(=O)-CoA
Diacylglycerol
CoA
Triacylglycerol

16. R-C(=O)-ACP or R-C(=O)-CoA
ACP or CoA
Glycerol-3-P
1-acyl-glycerol-3-P
R-C(=O)-ACP or R-C(=O)-CoA
CTP
ACP or CoA
PPi
Phosphatidic acid
inositol
CDP-choline or CDP-ethanolamine
CDP-diacylglycerol
CMP
CMP
phosphatidyl-inositol
phosphatidyl-choline or -ethanolamine