Different organs have different energy and metabolic fuel requirements. Match the organs listed below with the fuel sources each is able to utilize. Although fuel sources can change depending on the metabolic stage of the organism (e. g., starving vs. well-fed), here consider all potential fuel sources for each organ. A) Brain: B) Heart: C) Liver:

brain-

Glucose is the major fuel for the brain metabolism to supply energy for synaptic transmissions. Average of - 120g/day. However during hypoglacemia, keto bodies can be used by the brain for energy supply.

the fuel stores of the brain is very low because of high biochemical activities of the brain which need to be supplied with contant fuel. Although it stores little Glycogen, most fuel supply to the brain is from the circulating glucose in the blood.

Heart.

the high energy consuming activities of the heart ensured that molecules with abundant energy supply e. g fatty acids from lipids digestion is preferred. Keto bodies, acetoacetate and lactate can also be fuel. Glucose is last on the scale of preference for the heart as fuel.

It does not reserve or export any fuel.

Liver.

the complex metabolic and multi functional activities of the liver required constant supply of energy in all available forms. Thus glucose, Amino acids and fatty acids are sources of fuel for the liver.

The liver fuel reserve is in the form of glycogen which is stimulated by glucagon to convert to glucose during condition of hypoglycemia. Triacylglycerols is another fuel reserve.

Generally as products of metabolic activities in the liver, fatty acid from lipid metabolisms, Glucose from gluconeogenesis, and glycogensis, and ketone bodies are the export sources.