Lipolysis/Beta Oxidation

Step 1 of Lipolysis

ATGL catalyzes Triacylglycerols to Diacylglycerols

Product: Free fatty acid

Step 2 of Lipolysis

HSL catalyzes Diacylglycerols to Monoacylglycerols

Product: Free fatty acid

Step 3 of Lipolysis

MGL catalyzes Monoacylgycerol to glycerol

Product: Free fatty acid

All the Fatty Acids produced in Lipolysis

Can be fed into beta oxidation

Glycerol from Lipolysis

Glycerol Kinase catalyzes Glycerol to G3P

Product: ATP → ADP

G3P → DHAP

Glycerol 3 Phosphate Dehydrogenase will catalyze G3P → DHAP

Product: NAD → NADH

DHAP → Glyceraldehyde 3 Phosphate

Triose Phosphate Isomerase catalyzes DHAP to glyceraldehyde 3 Phosphate

Before Beta Oxidation Can Begin

1) Free fatty acid → Fatty acyl CoA

2) Carnitine Shuttle

Free Fatty Acid → Fatty Acyl CoA

Acyl CoA Synthetase catalyzes free fatty acids → fatty acyl CoA.

Products: ATP → ADP

Fatty Acyl CoA → Fatty Acyl Carnitine

Carnitine Acetyl Transferase 1 Swaps the CoA group with a Carnitine, allowing the fatty acyl CoA to be moved to the mitochondria for Beta oxidation

Carnitine Acetyl Transferase 2

Once fatty acyl carnitine is in the mitochondria, carnitine acetyl transferase 2 will swap the carnitine back with the CoA

1. Fatty Acyl CoA → Trans Enoyl CoA

Acyl CoA dehydrogenase

Products: FADH2

2. Trans Enoyl CoA → Beta Hydroxyacyl CoA

Enoyl CoA Hydratase

Reagents: H2O

3. Beta Hydroxyacyl CoA → Beta Keto Acyl CoA

L-Hydroxyacyl CoA Dehydrogenase

Product: NADH

4. Beta Keto Acyl CoA → Fatty Acyl CoA

Thiolase

Products: Acetyl CoA

Acetyl CoA from Beta Oxidation

Can be fed into Kreb’s Cycle