NANP Board Practice Exam 2025 - Free NANP Board Practice Questions and Study Guide

Mitochondria transport branched-chain amino acids (BCAAs) primarily to utilize them as substrates in aerobic energy production. BCAAs, which include leucine, isoleucine, and valine, play a significant role in energy metabolism, especially during periods of increased energy demand, such as exercise.

In the mitochondria, BCAAs can be catabolized to produce intermediates that enter the citric acid cycle (Krebs cycle), contributing to ATP production. This is essential for maintaining energy homeostasis in cells, particularly in muscle tissue, where BCAAs may serve as an important source of energy.

While other options might touch on various metabolic and physiological processes, they do not directly reflect the primary role of mitochondria in energy production. For instance, BCAAs are not converted into methionine, nor are they primarily synthesized into fatty acids or used for neutralizing toxins. Instead, their main function in the mitochondria is to serve as important substrates that help fuel the aerobic production of ATP.