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urban_flavaz
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#1
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#1
hi, could come sum1 plz explain how the bohr effect occurs? thanks
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oxymoron
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#2
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What level is this for?

I'll assume A level for now ...

You have the saturation curve for Haemoglobin (sigmoidal in shape). The Bohr effect occurs in the presence of decreased pH, and it causes the curve to shift to the right (ie for the same ppO2, you now have less saturation of Haemoglobin). This explains why a lower pH promotes dumping of oxygen (useful as pH in tissues is about 0.3 units lower than in the lungs --> dumping of oxygen in tissues).

If you still don't understand or want more detail ... just ask
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fairieboi
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and the pH is low because of the way CO2 is carried in blood - when it enters red blood cells it is converted into carbonic acid, which dissociates forming protons (more protons = lower pH) and hydrogencarbonate ions. the protons are 'mopped up' by the haemoglobin to form haemoglobinic acid (HHb), which forces the haemoglobin to release its oxygen load
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oxymoron
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Yes ... actually, in a little more detail (NOT needed for A level though). Hb exists in two forms, the T form (with a lower affinity for oxygen) and the R form (with a higher O2 affinity)

H+ forces it into the T form which is how the oxygen affinity is decreased, whereas in the lungs the higher ppO2 forces it into the R form ... releasing the proton to combine with the HCO3- to form CO2 which can diffuse across the alveolus wall.
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fairieboi
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(Original post by oxymoron)
Yes ... actually, in a little more detail (NOT needed for A level though). Hb exists in two forms, the T form (with a lower affinity for oxygen) and the R form (with a higher O2 affinity)

H+ forces it into the T form which is how the oxygen affinity is decreased, whereas in the lungs the higher ppO2 forces it into the R form ... releasing the proton to combine with the HCO3- to form CO2 which can diffuse across the alveolus wall.
hmmm. i kind of wish i was doing a science degree ;-/
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oxymoron
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(Original post by fairieboi)
hmmm. i kind of wish i was doing a science degree ;-/
and I wish I was doing an arts one :p:

No only joking ... but sometimes I do long for a lie-in!!
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