Questions: Which two amino acids are the most abundant and can be used directly to generate energy? (Select all that apply, no partial credit.) Alanine Citrulline Gamma aminobutyric acid Glutamine Ornithine

The answer is Alanine and Glutamine.

Explanation:

1. Alanine: Alanine is one of the most abundant amino acids in the bloodstream and plays a significant role in energy metabolism. It can be converted into pyruvate, which is a key intermediate in the energy production pathways, such as glycolysis and the citric acid cycle.

2. Citrulline: Citrulline is not directly used for energy production. It is primarily involved in the urea cycle and nitric oxide production.

3. Gamma aminobutyric acid (GABA): GABA is primarily a neurotransmitter and is not directly involved in energy production.

4. Glutamine: Glutamine is the most abundant amino acid in the body and can be converted into glutamate, which can then enter the citric acid cycle as alpha-ketoglutarate, contributing to energy production.

5. Ornithine: Ornithine is involved in the urea cycle and is not directly used for energy production.

In summary, Alanine and Glutamine are the two amino acids from the list that are most abundant and can be directly used to generate energy.