Answer to Question #150012 in Human Anatomy and Physiology for Roshelle

Question

How many times must a molecule of oxygen pass through a cell surface membrane as it diffuses from inside an alveolus, through a cell in the capillary wall, to bind to a molecule of haemoglobin?Explain

Answer 1

There is red-coloured pigment in the red blood cells called haemoglobin which increases the carrying capacity of the blood between 65 and 70 times. Each red blood cells contain about 250 million haemoglobin molecules. Oxygen concentration in cells is low i.e when leaving the lungs blood is 97% saturated with oxygen, so oxygen diffuses from the blood to the cells when it reaches the capillaries.