The metabolic fate of fatty acids is dependent on two enzymes, carnitine acyltransferase i and acetyl-coa carboxylase. carnitine acyltransferase i facilitates the transport of fatty acids to the mitochondria for β oxidation, whereas acetyl-coa carboxylase catalyzes the first reaction in the fatty acid synthesis pathway. the amp-activated protein kinase (ampk) regulates the activity of acetyl-coa carboxylase by phosphorylating a specific serine residue. mutation of this regulatory serine to alanine or aspartate would be expected to have different effects on the regulation of acetyl-coa carboxylase. select the statements that describe the expected effects of mutations of the regulatory serine.

The correct answer is the last statement.

If the regulatory serine is mutated to alanine, then acetyl-CoA carboxylase will get activated spontaneously and will produce malonyl-CoA. The increased concentrations of malonyl-CoA will obstruct the oxidation of fatty acids by preventing the entry of fatty acids into the mitochondria.

It is because the AMP-activated protein kinase phosphorylates the serine residues of acetyl-CoA carboxylase to inactivate it. If a mutation occurs in such residues, then the AMPL cannot phosphorylate acetyl-CoA carboxylase and this enzyme will get activated spontaneously.

In such a situation, there will be more than sufficient production of malonyl-CoA, which will inhibit the admittance of more fatty acid getting inside the mitochondria; this will indirectly prevent the oxidation of fatty acids.