Fatty Acid Synthesis

How do we make Fat from excess sugar?



Glucose goes through glycolysis to pyruvate.
PDH is activated by insulin signaling. Acetyl CoA is combined with Oxaloacetate to produce Citrate.
Citrate moves out of the mitochondria via the Citrate Shuttle, and Acetyl CoA is reformed
Acetyl CoA is transformed to Malonyl CoA (Negative feedback prevents Beta Oxidation)

FA synthesis is produced by Fatty Acid Synthase – works as a dimer – Multifunctional protein
Steps in FA Synthesis:
  1. Condensation
2. Reduction
3. Dehydration
4. Reduction
REPEAT
Pattern repeats until you obtain a 16 carbon Fatty Acid chain
  8 Acetyl CoA + 7ATP + 14NADPH  YIELDS  1 Palmitate, 14 NADP, 8 CoA, 7 ADP

Of the 14NADPH needed, 8 come from Oxaloacetate being converted to Malate.
The other 6 Come from the Pentose Phosphate shunt