There are mainly four recurring steps of the entire process of beta oxidation of fatty acid catabolism. However, the activation of fatty acids is quite necessary before that. The fatty acids are able to penetrate the plasma membrane because of the high fat solubility and poor water solubility of the plasma membranes. A fatty acid can react with ATP after it gets in the cytosol, and give a fatty acyl adenylate in addition to inorganic pyrophosphate. It is this reactive acyl adenylate that reacts with free coenzyme A in order to produce fatty acyl-CoA ester and AMP.
The first step of fatty acid catabolism or beta oxidation is the oxidation of the fatty acid by the Acyl-CoA- Dehydrogenease. A double bond is formed between the C-2 and C-3. The purpose that the enzyme serves is to catalyze the process of formation.
In the second step of fatty acid catabolism the bond between the C-2 and C-3 goes through the process of hydration. This is a stereospecific reaction that forms only the L isomer. The third step of fatty acid breakdown is the oxidation of L-beta-hydroxyacyl CoA by NAD+. In this process the hydroxyl group is converted into a keto group.
The last step of catabolism of fatty acid is called Thiolysis. It is the cleavage of beta-ketocyl CoA by the thiol group of a different molecule of CoA. It is between the C-2 and C-3 that the thiol is inserted. (Miles, 2003)
Aerobic respiration is one kind of ce ...