Question

What fuel do the brain and nerve tissues prefer? And what can red blood cells use?

1) Glucose and oxygen; nothing else
2) Fatty acids and glucose; nothing else
3) Amino acids and glucose; nothing else
4) Ketones and oxygen; nothing else

Answer 1

The brain and nerve tissues prefer glucose, which is also the only energy source for red blood cells. In a starvation state, the brain can use ketones.

Step-by-step explanation:

The preferred fuel for the brain and nerve tissues is glucose, and this is also the only substance that red blood cells can utilize for energy. During the state of starvation or when glucose is limited, however, the body can switch to ketones to satisfy the energy needs of the brain and other glucose-dependent organs. While most cells in the body can utilize fatty acids for energy, red blood cells and nerve cells are constrained in their fuel choice due to the blood-brain barrier and their metabolic requirements.