ACE Personal Trainer Practice Exam

What is the primary function of mitochondria in cells?

1. Protein synthesis

2. Aerobic metabolism

3. Lipid storage

4. Waste elimination

The correct answer is: Aerobic metabolism

The primary function of mitochondria in cells is aerobic metabolism. Mitochondria are often referred to as the "powerhouses" of the cell because they play a crucial role in the production of adenosine triphosphate (ATP), which is the energy currency of the cell. This process occurs through aerobic respiration, where oxygen is used to convert nutrients, primarily glucose and fatty acids, into ATP. Mitochondria contain their own DNA and are involved in several metabolic pathways, including the citric acid cycle and oxidative phosphorylation, which are essential for generating ATP. This energy is then utilized by the cell for various functions, including muscle contractions, neuronal activity, and biosynthesis of macromolecules. In contrast, while other cellular processes such as protein synthesis, lipid storage, and waste elimination are essential functions of the cell, they are not the primary roles of mitochondria. Protein synthesis occurs predominantly in ribosomes, lipid storage is managed by adipocytes and other cells, and waste elimination involves cellular mechanisms carried out in various organelles such as lysosomes, not specifically through mitochondrial activity.