why do your cells need oxygen?

Cells need oxygen because oxygen plays a crucial role in aerobic cellular respiration, the process by which cells generate energy. Oxygen acts as the final electron acceptor in the electron transport chain inside mitochondria, allowing the production of adenosine triphosphate (ATP), which is the main energy currency used by cells for all their functions. Without oxygen, cells cannot efficiently produce ATP, which is essential for processes such as transporting materials, cell division, and catalyzing biochemical reactions. This is why aerobic organisms, including humans, need oxygen to survive and why lack of oxygen causes cells to die. Oxygen combines with electrons and hydrogen ions at the end of the chain to form water, maintaining the flow of electrons necessary to generate the hydrogen ion gradient that powers ATP synthesis.