The fatty acid intermediates of synthesis are linked to sulfhydryl groups of acyl carrier protein (ACP) through covalent bonds. They link to the sulfydryl terminus of a phosphopantetheine group. During synthesis, the intermediates are linked to the serine residue of the acyl carrier protein.
The break down of fatty acid include intermediates that are covalently bonded to slufydryl group of coenzyme A. The intermediates of fatty acid degradation are attached to coenzyme A.