Oxygen-Hemoglobin Dissociation Curve

The oxygen-hemoglobin dissociation curve illustrates how hemoglobin in red blood cells binds and releases oxygen. When oxygen levels are high, hemoglobin easily picks up oxygen in the lungs. As blood circulates to tissues where oxygen is low, hemoglobin releases oxygen to meet the needs of cells. The curve is shaped like an "S," showing that hemoglobin binds oxygen strongly when oxygen is abundant and releases it more readily when oxygen levels drop. This flexible binding helps efficiently load oxygen in the lungs and unload it in the tissues, supporting proper oxygen delivery throughout the body.