Question

Mention if the following statements are false or true and justify your answer

a. Biotin is required for the activity of fatty acid synthase
b. The reaction of condensation in the synthesis of fatty acids is enhanced by the decarboxylation of malonyl-CoA
c. The synthesis of fatty acids does not depend on ATP
d. Palmitate is the final product of fatty acid synthase
e. All the activities of the enzyme required for the synthesis of fatty acids in mammals are in a single polypeptide chain
f. The fatty acid arachidonate is a precursor of signaling molecules
g. Acetyl-CoA carboxylase is inhibited by citrate.

Answer 1

Biotin is necessary for acetyl-CoA carboxylase, not fatty acid synthase, and fatty acid synthesis is ATP-dependent. Palmitate is the final product of fatty acid synthase, and the enzyme complex in mammals is formed from a single polypeptide chain. Arachidonate is a precursor to signaling molecules, and acetyl-CoA carboxylase is activated by citrate.

Step-by-step explanation:

The statement biotin is required for the activity of fatty acid synthase is false;

biotin is required for acetyl-CoA carboxylase, the enzyme that catalyzes the formation of malonyl-CoA from acetyl-CoA – a precursor to the fatty acid synthase reaction.

The statement that the reaction of condensation in the synthesis of fatty acids is enhanced by the decarboxylation of malonyl-CoA is true;

condensation involves the decarboxylation of malonyl-CoA to extend the fatty acid chain.

The statement the synthesis of fatty acids does not depend on ATP is false;

activation of fatty acids to acyl-CoA is an ATP-dependent process.

The statement that palmitate is the final product of fatty acid synthase is true, as synthesis halts after production of the 16 carbon fatty acid palmitate.

The statement that all activities of the enzyme required for the synthesis of fatty acids in mammals are in a single polypeptide chain is true;

fatty acid synthase is a multifunctional enzyme complex formed from a single polypeptide chain that acts as a dimer.

Lastly, the statements that the fatty acid arachidonate is a precursor of signaling molecules and acetyl-CoA carboxylase is inhibited by citrate are false;

arachidonate is indeed a precursor of eicosanoids, which are signaling molecules, whereas acetyl-CoA carboxylase is actually activated, not inhibited, by citrate.