Under normal circumstances, the only source of energy used by the brain is
A) glucose.
B) fatty acids.
C) protein.
D) glycogen.

Question

Quizplus · Accepted Answer

Glucose is the main source of energy used by the brain, which requires a continuous supply of glucose to function properly. While the brain can also use ketones and some amino acids as a source of energy during fasting or starvation, glucose is the preferred and most efficient fuel for the brain. Fatty acids can also provide energy, but they cannot cross the blood-brain barrier, which means that they cannot be used directly by the brain. Protein can be broken down into amino acids, which can be used as an energy source, but this is not the primary way that the brain gets energy. Glycogen is a storage form of glucose in the liver and muscles, which can be broken down into glucose and used by the body and brain as an energy source when needed. However, it is not a direct source of energy for the brain.

Under Normal Circumstances, the Only Source of Energy Used by the Brain