Question

There can be more than one correct answer.

21. The partial pressure of oxygen is the major factor that determines

A. the shape of the oxygen-hemoglobin dissociation curve
B. how much oxygen will combine with hemoglobin
C. how much oxygen will be released from hemoglobin

D. how far the oxygen-hemoglobin dissociation curve will shift to the left

E. how far the oxygen-hemoglobin dissociation curve will shift to the right

Answer 1

* Answers are optiin A, B and C.

A) The more oxygen is bounded to Hb as the pO2 increases until the maximum amount. As the limit is reached, less molecules get attached as the heamoglobin gets saturated gives the curve a sigmoidal or S shape.

B) The amount of oxygen combines with heamoglobin is determined by the partial pressure of oxygen in relation to oxygen-heamoglobin dissociation curve. The pO2 increases, the affinity of oxygen bound to heamoglobin increases.

C) The reduced partial pressure of oxygen in tissues causes the dissociation of O2 from heamoglobin inorder to transfer into the tissues.

* The pO2 doesn't plays any role in right or left shift of O2-hemoglobin dissociation curve. Temperature, pCo2, pH and DPG effects the shift of curve.