Question

Question:Summarize the chemical reactions that occur in each round ofβoxidation. Explain why the process is calledβoxidation.

Short answer

The four reactions occurring during beta oxidation are dehydrogenation, hydration, oxidation, and thiolysis reaction. The beta carbon of the fatty acyl CoA gets oxidized to a keto group, hence termed $\beta$-oxidation

Step-by-step solution

Four reactions involved in the degradation of fatty acyl CoA

There are four reactions involved in the degradation of fatty acyl CoA to acetyl CoA via oxidation.

1. Fatty acyl CoA, by the action of acyl-CoA dehydrogenase (AD), a flavoenzyme, gives a trans double bond product. The removal of the hydrogen atom from the acyl-CoA during the dehydrogenation reaction gives the trans-double bonded product.
2. The double bond of the trans- product gets hydrated in the presence of enoyl-CoA hydratase (EH), giving the product 3-L-hydroxyacyl-CoA.
3. 3-L-hydroxyacyl-CoA will convert to -ketoacyl-CoA by-dependent dehydrogenation in the presence of3-L-hydroxyacyl-CoA dehydrogenase (HAD).
4. $\beta$-ketoacyl-CoA undergoes a $C_{\alpha }-C_{\beta }$cleavage through thiolysis reaction in the presence of -$\beta$ketoacyl-CoA thiolase (KT) to form acetyl CoA.

Why the process is β oxidation

The conversion of Fatty acyl CoA to acetyl CoA is called-oxidation because thecarbon of the fatty acyl CoA is oxidized to a keto group.