Acyl-coa + fad ↔ trans-δ2-enoyl-coa + fadh2 (note: the double tipped arrow means forward and reverse)

this is the first reaction of β-oxidation. which of the following statements about this reaction is true.

a. acyl-coa is the electron acceptor.
b. trans-δ2-enoyl-coa has a lower affinity for electrons than fadh2.
c. fad is the oxidizing agent.
d. fadh2 is spontaneously reduced.

c) FAD is the oxidizing agent

Explanation:

The β-oxidation is a catabolic process where fatty acids are degraded into a final product: Acetil-CoA. In order this process occurres, the fatty acid chain is being removed from a pair of carbon atoms on each cycle

Before the β-oxidation takes place, the fatty acid molecule should be activated, so it can go through the mitochondrial membrane into (via a carnitine translocator)

Once the activated molecule is inside the mitochondrial matrix, it can go through the β-oxidation: the first step is the oxidation of the fatty acid, with the enzyme Acyl-CoA-dehydrogenase (this enzyme catalyzes the creation of a double bond between carbon-2 and carbon-3.

This enzyme has attached a coenzyme: FAD, which takes the electrons (from the fatty acid oxidation) and becomes a reduced component: FADH2:

Acyl-CoA + FAD ↔ trans-Δ2-enoyl-CoA + FADH2