Bio Chemistry

BIOCHEMISTRY 3(2+1)

Lesson 23 : Fatty acid Degradation

Activation and transport into mitochondria

Fatty acids must be activated before they can be carried into the mitochondria, where fatty acid oxidation occurs. This process occurs in two steps catalyzed by the enzyme fatty acyl-CoA synthetase.

Transport into the mitochondrial matrix

Once activated, the acyl CoA is transported into the mitochondrial matrix. This occurs via a series of similar steps:

1. Acyl CoA is conjugated to carnitine by carnitine acyltransferase (palmitoyltransferase) I located on the outer mitochondrial membrane
2. Acyl carnitine is shuttled inside by a translocase
3. Acyl carnitine is converted to acyl CoA by carnitine acyltransferase (palmitoyltransferase) II located on the inner mitochondrial membrane. The liberated carnitine returns to the cytosol.