Before the formation of oxyhaemoglobin, the O 2 has to pass through _________ membranes from the alveolar air.

Question

Before the formation of oxyhaemoglobin, the O 2 ​ has to pass through _________ membranes from the alveolar air.

TestHub · Accepted Answer

To form oxyhaemoglobin, oxygen from the alveolar air must diffuse into the red blood cells (RBCs) where haemoglobin is present. During this process, the $O_{2}$ molecule has to pass through the following three cellular membranes:

1. Squamous epithelium of the alveoli (Alveolar membrane)
2. Endothelium of the alveolar capillaries (Capillary membrane)
3. Plasma membrane of the red blood cell (RBC membrane)

Note: The basement substance present between the alveolar epithelium and capillary endothelium is a non-cellular matrix layer and is not counted as a cellular membrane in this context.

Therefore, oxygen passes through $3$ membranes.

Answer: $3$

Biology - Breathing and Exchange of Gases Question with Solution | TestHub

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