Final answer:
The acyl group in coenzyme A is linked through a thioester bond.
Step-by-step explanation:
The acyl group in coenzyme A is linked through a thioester bond. Coenzyme A (CoA) has a reactive thiol (-SH) group that forms a high-energy thioester bond with acyl groups. This bond allows for the transfer of the acyl group to other compounds during various biological processes, such as fatty acid synthesis and the catabolism of carbohydrates.
For example, in the synthesis of fatty acids, the acetyl group from Ac-S-CoA is transferred to an acyl carrier protein (ACP), which is a step in the process. In the catabolism of carbohydrates, pyruvate transfers its acetyl group to HS-CoA, forming Ac-S-CoA. This thioester bond is instrumental in the metabolism of fatty acids, where Acyl-CoA is transported into mitochondria and undergoes ß-oxidation.