Here's why:

* Mitochondria are the "powerhouses" of the cell. They are responsible for producing ATP (adenosine triphosphate), the primary energy currency of cells.

* Aerobic respiration requires oxygen. Mitochondria have specialized enzymes and structures that allow them to utilize oxygen to break down glucose and generate ATP.

* Glycolysis, the first stage of cellular respiration, occurs in the cytoplasm. However, the remaining stages (Krebs cycle and electron transport chain) take place within the mitochondria.

Let me know if you have any other questions!