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Q42 Single choice

Continued consumption of calories in excess of energy expenditure will eventually lead to obesity, a current major health problem in the United States. A major contributing factor in obesity is a disorder in fuel partitioning, as evidenced by a lower rate of fat oxidation in obese individuals.

Which of the following situations would best explain a reduction in overall fat metabolism in these individuals?

A
An increase in the hepatic ATP/ adenosine diphosphate (ADP) ratio increases incorporation of carbon into fatty acids by causing an inhibition in acetyl-CoA oxidation in the TCA cycle.
B
Decreased hepatic gluconeogenesis which requires acetyl-CoA from fatty acid oxidation, thus fat oxidation is secondarily inhibited.
C
Increased levels of malonyl-CoA occur in these individuals leading to inhibition of carnitine palmitoyltransferase I.
D
Insulin-induced decrease in the activity of acetyl-CoA carboxylase (ACC) causing reduction in fatty acid synthesis.
E
Insulin-induced repression of fatty acid synthase (FAS) activity.

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