: Select the Mitochondrion and check Show closeup. What happens inside the mitochondrion?

Inside the mitochondrion, cellular respiration takes place, where glucose and oxygen are converted into energy in the form of adenosine triphosphate (ATP). This process involves several steps, including the citric acid cycle and the electron transport chain. The mitochondrion is often referred to as the "powerhouse" of the cell because it produces the majority of the cell's ATP, which is necessary for various cellular functions.