Question

The primary fuel source for the brain after a 48 hour fast is

1: essential fatty acids.
2: ketone bodies.
3: carbohydrates.
4: amino acids.

Answer 1

The primary fuel source for the brain after a 48-hour fast is ketone bodies, which are synthesized from fatty acids and serve as a metabolic fuel for the brain and other organs.

Step-by-step explanation:

The primary fuel source for the brain after a 48-hour fast is ketone bodies. After the exhaustion of the glycogen reserve, fatty acids become the principal metabolic fuel.

The liver then synthesizes ketone bodies from precursors obtained from fatty acid breakdown, which are released into the blood for use as a metabolic fuel by the brain and other organs.