Question

Which of the following amino acids cannot provide a substrate for gluconeogenesis?

• A. \( \text{Leucine} \)
• B. \( \text{Tryptophan} \)
• C. \( \text{Histidine} \)
• D. \( \text{Isoleucine} \)

Hint:

Ketogenic amino acids contribute to ketone body formation, essential for energy metabolism during fasting states.

Answer 1

The Correct Option is A

Leucine is classified as a purely ketogenic amino acid, meaning it is exclusively metabolized into ketone bodies. It cannot be converted into glucose via gluconeogenesis, unlike glucogenic amino acids such as histidine or tryptophan. This distinction is important in metabolic disorders and energy balance.