NANP Board Practice Exam

For what primary reason do mitochondria transport BCAAs?

1. To convert them into methionine

2. To synthesize fatty acids

3. To neutralize toxins

4. To use them as substrates in aerobic energy production

The correct answer is: To convert them into methionine

Mitochondria play a crucial role in energy metabolism, particularly in the context of branched-chain amino acids (BCAAs). The primary reason mitochondria transport BCAAs is to use them as substrates in aerobic energy production. This process involves the breakdown of these amino acids for energy, especially during periods of increased demand, such as exercise. In contrast, while methionine is an important amino acid, it is primarily synthesized from homocysteine and does not directly relate to BCAAs being transported by mitochondria. Additionally, synthesizing fatty acids and neutralizing toxins involve different metabolic pathways and processes. Mitochondria are essential for energy production, and utilizing BCAAs as substrates for aerobic respiration aligns with their fundamental role in cellular metabolism.