beta oxidation and fatty acid synthesis

(fatty)-acyl-CoA

Acyl-CoA Dehydrogenase

(fatty)-acyl-CoA → Enoyl-CoA

• FAD → FADH₂

Enoyl-CoA

Enoyl-CoA Hydrotase

Enoyl-CoA → ß-hydroxy-acyl-CoA

• +H2O

ß-hydroxy-acyl-CoA

ß-hydroxy-acyl-CoA dehydrogenase

ß-hydroxy-acyl-CoA → ß-keto-acyl-CoA

• NAD⁺ → NADH+ H⁺

ß-keto-acyl-CoA

thiolase

ß-keto-acyl-CoA → acyl-CoA AND Acetyl-CoA

• + SCoA

acyl-CoA

Acetyl-CoA

Acetyl-FAS

Malonyl ACP

ß-ketoacyl ACP synthase

Acetyl-FAS AND Malonyl ACP → ß-ketoacyl ACP

• CO2 leaves

ß-ketoacyl ACP

ß-ketoacyl ACP reductase

ß-ketoacyl ACP → ß-hydroxy acyl ACP

• NADPH + H⁺ → NADP+

ß-hydroxy acyl ACP

ß-hydroxy acyl ACP dyhydratase

ß-hydroxy acyl ACP → enoyl-ACP

• H2O leaves

enoyl-ACP

enoyl-ACP reductase

enoyl-ACP → Acyl ACP

• NADPH + H⁺ → NADP⁺

Acyl ACP

thioesterase

enoyl-ACP → desired fatty acid

• + H2O

• cuts SACP off the chain

Fatty acid synthesis processes

1. Transfer acetyl-CoA out from mitochondria to cytoplasm

2. Activate acetyl-CoA to form malonyl-CoA

3. Make fatty acid by adding 2 carbon units at a time

Acetyl-CoA activation

Acetyl-CoA carboxylase (ACC)

- Rate-limiting step!

- Requires ATP and biotin (carboxyl carrier)

Acetyl CoA ⟶ malonyl-CoA

• ATP → ADP