(Solved): Acetyl-CoA produced by the pyruvate dehydrogenase (PDH) complex can enter the citric acid cycle or c ...

Acetyl-CoA produced by the pyruvate dehydrogenase (PDH) complex can enter the citric acid cycle or can be used to synthesize fatty acids. Hepatocytes (liver cells) in culture were incubated with fatty acids and the activity of PDH kinase was measured. Would you expect fatty acids to stimulate or inhibit the kinase or have no effect?

• A. None of the choices are correct.
• B. Fatty acids would have no effect on PDH kinase, which catalyzes the phosphorylation and inactivation of the PDH complex. Acetyl-CoA is not required for fatty acid synthesis if the cellular concentration of fatty acids is high.
• C. Fatty acids would stimulate the PDH kinase, which catalyzes the phosphorylation and inactivation of the PDH complex. Acetyl-CoA is not required for fatty acid synthesis if the cellular concentration of fatty acids is high. Instead, pyruvate can be used as a reactant in other metabolic pathways
• D. Fatty acids would inhibit the PDH kinase, which catalyzes the phosphorylation and inactivation of the PDH complex. Acetyl-CoA is required for fatty acid synthesis if the cellular concentration of fatty acids is high.