AQA BIOL2~3rd June 2013~AS Biology (Now Closed) Watch
How haemoglobin loads oxygen in the lungs and unloads in a tissue cell?:
Firstly you a low partial pressure in the lungs, so haemoglobin will have a high affinity for oxygen, so oxygen therefore binds to the haemoglobin molecule by alosteric inhibition. Oxyhemoglobin is now formed, when it reaches the reaches the respiring tissues, you have a high partial pressure, therefore you have a low affinity of oxygen. Consequently, oxyhemoglobin unload the oxygen to the respiring tissues which means cellular respiration occurs. This means that carbon dioxide is produced, which happens to lower the ph of the blood, causing a higher partial pressure, so the cells would rapidly need oxygen to be unloaded from haemoglobin, in order to compensate for this production of carbon dioxide.
This should get you 6 marks, probably need to put half of what I put
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