<prompt> One hemoglobin molecule can carry how many oxygen molecules?1234  <response>: Ans. D 4O2 TRANSPORTTransport occurs via two processes: Hemoglobin bound O2 99 Dissolved O2 1 1 Hb can carry 4 oxygen molecules. Molecule of oxygen bound to hemoglobin depends on saturation of Hb SaO2 SpO2 with oxygen. SaO2 depends on PaO2 CALCULATION OF HB-BOUND O2 In arterial bloodIn venous blood 97 hemoglobin is saturated with oxygen, at PaO2 of 95 mm Hg. With this saturation, 1 g of Hb, contains 1.34 mL of O2 . Therefore 100 mL of blood contains 20.1 mL of oxygen when normal Hb 15 gm When hemoglobin is 100 saturated with O2 , hemoglobin binds 1.39 mL O2 per gm of Hb At PvO2 of 40 mm Hg, Hb is only 75 saturated SO2 75. Therefore, 100 mL of venous blood would carry 14.4 mL of O2 