Question

Oxyhemoglobin is an unstable substance and breaks down easily to oxygen and hemoglobin. Because of its instability, oxyhemoglobin
(a) Can carry extra oxygen
(b) Readily pick up oxygen from lungs
(c) Readily give up oxygen to body cells
(d) Is quickly broken down in the liver

Answer 1

Hint: Oxygen carried by hemoglobin delivers oxygen to the tissues by dissociation of oxyhemoglobin due to the difference in the partial pressure of oxygen and carbon dioxide in the systemic capillaries and tissues

Complete answer:
Oxygen is transported from the lungs to the tissues through the plasma and RBC of the blood. 100ml of blood can deliver 5ml of oxygen to the tissues under normal physiological conditions. Oxygen binds to hemoglobin in a reversible manner to form oxyhemoglobin making the blood bright red in color. Oxyhemoglobin is unstable and easily dissociates into oxygen and hemoglobin. This feature of oxyhemoglobin is used to deliver oxygen to the tissues. Due to the high affinity of hemoglobin towards carbon dioxide as soon as oxyhemoglobin dissociates and delivers oxygen to the tissues, it carries carbon dioxide in the form of carboxyhemoglobin to the lungs.

Additional Information:
- A rise in carbon dioxide and a fall in the PH decreases the affinity of hemoglobin for oxygen. On the other hand, a fall in the partial pressure of carbon dioxide and a rise in PH increases the affinity of hemoglobin towards oxygen. This clearly indicates that oxygen gets bound to hemoglobin at the lungs and gets dissociates at the tissues
So, the correct answer is ‘readily give up oxygen to body cells’.

Note: The difference in the partial pressure of oxygen and carbon dioxide of oxygenated blood in systemic capillaries and tissues favors the diffusion of oxygen into the tissues
Hemoglobin without oxygen is purplish-bluish-red in color and when combined with oxygen it turns into bright red in color.