This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fuel in Fed, Fasting and Starvation, Subject name: Biochemistry
Ketone bodies are not used by which organ- 
Select and explain. 
A. Brain, B. Liver, C. Muscle, D. Hea
B: Liver
Answer: B: Liver 
Explanation: - In liver there is absence of thiophorase, first enzyme of ketone body utilization pathway. - So Liver also cannot utilize ketone bodies. - Brain, muscle and hea can use ketone bodies during starvation. Extra information: In RBC, there is no mitochondria and ketone body utilization pathway takes place in mitochondria. So, RBC cannot utilize ketone bodies