In Last couple of hours at the end of 48 hours of fasting, the main source of energy is:
Ans- A. Muscle glycogen In the last couple of hours in 48 hours fasting state, By 12-16 hours liver glycogen is used up. So liver glycogen is not the answer. Acetoacetate is the source of fuel in prolonged fasting that is after 48 hours. The nucleic acid can never be a metabolic fuel. Then Muscle Glycogen, here is how it can be the fuel =muscle glycogen is converted to Glucose-6-PO4 transferred to Glycolysis cycle, converted to pyruvate later transaminated to Alanine finally to the Liver for Gluconeogenesis. So the answer is muscle glycogen.
Muscle glycogen
Liver glycogen
Acetoacetate
Nucleic acids