1. Oxidation of fatty acids

2. Introduction Central energy yielding pathway in many tissues As fuel
Chemically inert
Releases lots of energy

3. Oxidation of fatty acids
Occurs in 3 steps
Oxidative removal of successive 2 carbon units in the form of acetyl CoA.
Acetyl groups enter Citric acid cycle to yield CO2 and H2O
NADH and FADH2 donate electron to the mitochondrial chain with ultimate phosphorylation of ADP to ATP.

4. Beta - Oxidation 4 enzyme catalyzed reactions take place
Dehydrogenation of Fatty acyl CoA producing double bond.
Addition of H2O to the double bond to form L- stereoisomer of Beta-Hydroxyacyl CoA.
Dehydrogenation to Beta ketoacyl CoA.
Thiolysis by thiloase catalyzed reaction to give off 2 C fragment of orig. F.Acid as Acetyl CoA.

6. TFP or Tri functional protein
For fatty acyl chain of 12 or more C, the reactions are catalyzed by a multienzyme complex associated with the inner mitochondrial memb., TFP.

7. Structure of TFP Heterodimer of Alpha4 & Beta4 subnits.
Alpha4 has 2 activities
Enoyl CoA hydratase
Beta-Hydroxyacyl-CoA dehydrogenase
Beta 4 - Thiolase activity.

8. Net reaction ( 16 – C palmitic acid ) Beta oxidation
Palmitoyl CoA + 23O2 +108Pi +108 ADP = CoA +108 ATP + 16CO2 + 23H2O
( The cost of activation of palmitate to palmitoyl CoA is 2 ATP,
So net gain is 106 ATP)

9. Beta oxidation of mono-unsat. Fatty acid
The side diagram shows the Beta oxid. Of Oleic Acid.

10. Oleate is an abundant 18-C mono-unsaturated fatty acid ( cis double bond at C-9 & C-10.
Conversion to oleoyl CoA by carnitine shunt
3 passes thr beta oxid. To yield 12 carbon unsat. Fatty acid as shown in fig
Isomerase enzyme converts cis form to trans
Further Beta oxid.

11. Beta oxidation of poly-unsaturated fatty acid

12. If no. of carbons are odd

13. Thank you!