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F A T T Y A C I D

SYNTHESIS

FATTY ACID SYNTHESIS is the assembly of long alkyl chains with a substrate called Acetyl-CoA. Such takes place in the cytoplasm where the process is initiated by the formation of acetoacetyl-ACP. Then, the elongation cycle proceeds with two carbons added on each time. The Acyl carrier protein is covalently bounded to the fatty acid and acts as a chaperone till the lipid is formed.

The formation of acetoacetyl- ACP is catalyzed by enzymes, but starts with acetyl-CoA as a substrate.

IMPORTANCE

Major source of energy
Precursors of essential substance in our body (structural and metabolic)
Defects in fatty acid metabolism involves disease

Elongation Cycle

1. Condensation of malonyl-CoA with acetoacetyl-ACP chain (+2C)

2. Use two NADPH to reduce the B-ketone and generate acyl-ACP molecule (2C+)

3. The acyl-ACP continues in elongation till the wanted chain length is achieved.

4. The fatty acid is transfered from the acyl-ACP to sn-glycerol-3-phosphate to make phosphatidic acid.

5. Then, we add the hydrophilic part to it.

NOTE_ the glycerol backgone of lipid is from dihydroxyacetone phosphate, which is reduced to sn-glycerol-3-phosphate with NADH

www.bact.wisc.edu/microtextbook/Metabolism/lipidSyn.html

Fatty Acid Overview

http://www.mcphu.edu/netbiochem/FattyAcids/image_index/