PSI Barbering Practice Exam

In which part of the cell does the majority of cellular respiration occur?

1. Nucleus

2. Mitochondria

3. Ribosomes

4. Cytoplasm

The correct answer is: Mitochondria

Cellular respiration primarily occurs in the mitochondria, which are often referred to as the "powerhouses" of the cell. This is where the processes of aerobic respiration—including the Krebs cycle and oxidative phosphorylation—take place. The mitochondria are uniquely structured with their own DNA and double membrane, which aids their function in energy production. While some steps of cellular respiration, such as glycolysis, occur in the cytoplasm, the significant stages that produce the majority of ATP (adenosine triphosphate) occur within the mitochondria. Hence, the role of the mitochondria in cellular respiration is crucial for meeting the energy demands of the cell. Understanding this process further highlights the importance of mitochondria in maintaining cellular health and energy levels.