The x-axis shows the partial pressure of oxygen (PO2). This is a measure of the amount of oxygen present in a tissue. The blue arrows on the x-axis show the partial pressure of oxygen in various tissues of the body. The y-axis shows the oxygen saturation of hemoglobin (O2 saturation). This is the percentage of oxygen-binding sites on hemoglobin molecules that are actually bound to oxygen. O saturation of hemoglobin (%) 100 80 60 40 20 Cooperative binding 10 20 30 40 50 60 70 80 90 100 tissue during exercise tissue at rest PO (mm Hg) lungs O saturation of hemoglobin (%) 100 80 60 40 20 0 0 Noncooperative binding 10 20 30 40 50 60 70 80 90 100 tissue during tissue exercise at rest PO2 (mm Hg) lungs 20% 30% 50% 70% 80% 100% Question 1. What is the O saturation in the lungs? 2. What is the O saturation in tissues at rest? 3. What percentage of O is delivered to tissues at rest? 4. What is the O saturation in exercising tissues? 5. What percentage of O is delivered to exercising tissues? Submit Hints My Answers Give Up Review Part Incorrect; Try Again; 3 attempts remaining Cooperative binding () G 100% 50% 50% 20% 20% Noncooperative binding 100% 70% 70% 50% 50% reset ? help