Final answer:
Under normal conditions, the percent saturation of hemoglobin with oxygen is between 95-99%, indicating that nearly all available heme sites in hemoglobin are occupied by oxygen.
Step-by-step explanation:
Under normal conditions, the percentage of the hemoglobin receptors that contain oxygen is generally between 95-99%. This level of percent saturation of hemoglobin means that nearly all the heme sites in the hemoglobin are occupied by oxygen molecules. When hemoglobin picks up oxygen in the lungs, it forms oxyhemoglobin (HbO₂), which is then transported to the body tissues. In tissues with lower oxygen pressure, hemoglobin releases oxygen and forms reduced hemoglobin (HHb). Hemoglobin's affinity for oxygen is part of a dynamic process: as the percent saturation of hemoglobin increases with more oxygen available, its affinity for further binding of oxygen increases, creating an S-shaped curve on a graph that charts oxygen saturation versus oxygen partial pressure.