You are examining feeding behavior in laboratory animals in response to the addition of a test organic molecule to their chow. Following consumption of the compound you discover that the animals loose interest in food. Additional experiments demonstrate that central metabolism of palmitic acid is reduced in these animals. Given these observations you believe that the test compound is most likely inhibiting which of the following hypothalamic enzymes?
A) acetyl-CoA carboxylase
B) carnitine palmitoyltransferase I
C) fatty acid synthase
D) malonyl-CoA decarboxylase
E) medium-chain acyl-CoA dehydrogenase

Question

Quizplus · Accepted Answer

Carnitine palmitoyltransferase I is involved in the transport of fatty acids into the mitochondria for β-oxidation. Inhibition of this enzyme would reduce the metabolism of palmitic acid, leading to decreased energy production and reduced interest in food. Fatty acids, specifically long-chain fatty acids via the formation of long-chain fatty acylCoAs, exert anorexigenic effects via the hypothalamus. Mitochondrial CPT-1 activity is involved in the central effects of fatty acids. Inhibition of hypothalamic CPT-1 leads to an increase in cytosolic long-chain acyl-CoA content and results in anorexigenic effects.

You Are Examining Feeding Behavior in Laboratory Animals in Response