Aerobic organisms depend on oxygen for aerobic respiration, which is essential for producing ATP and meeting the energy demands of the cell.

ATP is broken down, releasing a fixed amount of energy that can drive endothermic reactions within the cell.

The primary molecule synthesized during cellular respiration is ATP (adenosine triphosphate), which serves as the primary energy currency of the cell, fueling various cellular activities.

The breakdown of pyruvate occurs in the mitochondria during aerobic respiration, resulting in the production of three molecules of carbon dioxide and water.

In the absence of oxygen in muscle cells, pyruvate is converted into lactic acid, leading to the build-up of lactic acid, which causes muscle cramps during sudden activity.