In the alveoli, what does oxygen do?

In the alveoli, oxygen diffuses into the blood due to a concentration gradient. The alveoli are tiny air sacs in the lungs where gas exchange occurs. When air is inhaled, it fills the alveoli and has a higher concentration of oxygen compared to the blood in the capillaries surrounding these structures. This difference in concentration drives oxygen from the alveoli, where it is abundant, into the red blood cells in the bloodstream, where it is less concentrated. This process is essential for delivering oxygen to the body's tissues, enabling cellular respiration and energy production. The efficiency of this gas exchange is crucial for maintaining the body’s oxygen levels and overall metabolic functioning.