Why don't red blood cells use the oxygen they carry?

Red blood cells do not utilize the oxygen they carry because they do not have mitochondria. Mitochondria are the organelles responsible for energy production in cells through the process of aerobic respiration, which uses oxygen to generate ATP, the energy currency of the cell.

Since red blood cells are specialized for transporting oxygen rather than using it for their own metabolism, they lack these organelles. Instead, they generate energy through a less efficient anaerobic process that does not require oxygen. This allows them to efficiently transport oxygen from the lungs to tissues throughout the body without consuming it themselves. Thus, their structure and function are optimized for oxygen transport rather than utilization, ensuring that they can deliver oxygen to organs and tissues that need it.