This enzyme embedded in the peroxisomal membrane is responsible to activate fatty acids before undergoing beta-oxidation

The correct option is Acyl – CoA synthase.

Here is the step-by-step explanation of why this option is correct:

1. Understanding Fatty Acid Activation:
Before fatty acids can enter metabolic pathways like β-oxidation (beta-oxidation) to be broken down, they must first be chemically activated. This activation process involves attaching a coenzyme A (CoA) group to the free fatty acid, converting it into a fatty acyl-CoA molecule. This reaction requires energy, which is provided by the cleavage of ATP into AMP and pyrophosphate.

2. Role of Acyl-CoA Synthase:
The enzyme that catalyzes this critical activation step is acyl-CoA synthase (also referred to as acyl-CoA synthetase). To facilitate the metabolism of fatty acids within peroxisomes, this enzyme is embedded in the peroxisomal membrane, where it activates incoming fatty acids (especially long-chain and very-long-chain fatty acids) before they undergo β-oxidation inside the organelle.

3. Why the Other Options are Incorrect:
• Acyl-CoA oxidase: This enzyme catalyzes the first oxidation step of β-oxidation inside the peroxisome, but it acts on already-activated acyl-CoA, not free fatty acids.
• 3-ketothiolase: This enzyme catalyzes the final thiolytic cleavage step of the β-oxidation cycle.
• Fatty acid dehydrogenase: This term generally refers to enzymes involved in dehydrogenation/oxidation reactions rather than the initial activation/esterification of fatty acids with coenzyme A.