Bohr’s effect- The Bohr effect is a physiological phenomenon first described by Danish physiological Christian Bohr, stating that the “oxygen binding affinity of hemoglobin is inversely related to the concentration of carbon dioxide and hydrogen ion. #An increase in blood CO2 concentration which leads to decrease in blood pH will results in hemoglobin proteins releasing their oxygen load. #One of the factor that Bohr discovered was pH. He found that if the pH is lower than the normal, then hemoglobin does not bind oxygen. #And this effect of CO2 on oxygen dissociation curve is known as Bohr effect. Haldane effect- The Haldane effect is first discovered by John Scott Haldane. #The Haldane effect describe the phenomenon by which binding of oxygen to hemoglobin promotes the release of carbon dioxide. #Haldane effect is the mirror image of Bohr effect. #The decrease in carbon dioxide leads to increase in the pH, which result in hemoglobin picking up more oxygen. #This is a helpful biochemical feature which facilitates exchange of carbon dioxide for oxygen in the pulmonary and peripheral circulations.

1. Name Garima Thakur
MSc Zoology 1

2. The Bohr effect is a physiological phenomenon first
described by Danish physiological Christian Bohr, stating
that the “oxygen binding affinity of hemoglobin is inversely
related to the concentration of carbon dioxide and hydrogen
ion.
An increase in blood CO2 concentration which leads to
decrease in blood pH will results in hemoglobin proteins
releasing their oxygen load.
One of the factor that Bohr discovered was pH. He found
that if the pH is lower than the normal, then hemoglobin
does not bind oxygen.
And this effect of CO2 on oxygen dissociation curve is
known as Bohr effect.

4. 1. The Bohr effect takes place in the peripheral tissues. As the
peripheral tissue is metabolic active, TCA cycle is takes place in
it. The byproduct of TCA cycle is CO2.
2. So the partial pressure of CO2 will be higher in the tissues, then
the CO2 diffuse in the blood plasma and then into the red blood
cell.
3. As the CO2 goes into the RBC it combine with H2O and then
this combination will be catalyzed by enzyme known as carbonic
anhydrase.
4. And with that H2CO3 i.e. carbonic acid will form.
5. And then carbonic acid will spontaneously dissociate into H+
and HCO3- i.e. bicarbonate.
6. And then HCO3 will go out of red blood cell into the plasma as
the HCO3 goes in plasma the chloride ion will come in the red
blood cell that is a chloride shift.
7. If 100% CO2 is in the peripheral tissue than 85-90% will be
carried from peripheral tissue to lungs as bicarbonate. And 5%
will directly dissolved into the plasma and the remaining 10%
will go and bind directly with Hb molecule.
8. The Hb molecule in the RBC it came from the lungs, so red
blood cell will also carry 4 molecule of Oxygen.

5. • To remove oxygen molecule, the proton i.e. H+ will go
protonate histidine residual in Hb, this will lead to
increase in salt bridges and that will lead to stabilization
of T-State of Hb. Because of this 4 molecule of oxygen
will release from hemoglobin.
• And this whole mechanism is known as Bohr effect.

6. • The Haldane effect is first discovered by John Scott
Haldane.
• The Haldane effect describe the phenomenon by which
binding of oxygen to hemoglobin promotes the release of
carbon dioxide.
• Haldane effect is the mirror image of Bohr effect.
• The decrease in carbon dioxide leads to increase in the
pH, which result in hemoglobin picking up more oxygen.
• This is a helpful biochemical feature which facilitates
exchange of carbon dioxide for oxygen in the pulmonary
and peripheral circulations.

8. • RBC containing Hb which bind with H+ and 10% of CO2 are
carried to the lungs.
• In lungs, as we are respiring the alveoli has got oxygen 90mm
of Hg.
• Now the oxygen will get in the RBC.
• The bicarbonate which were in plasma will also come in the
lungs along with the RBC
• Because the partial pressure of Oxygen is 90mm of Hg that
itself is sufficient to load oxygen with the hemoglobin molecule.
• Due to the loading of oxygen with Hb, it will remove the H+ and
CO2 because of the breakage of salt bridges.
• Now as the H+ and CO2 is separated from Hb, oxygen bind
with Hb i.e. is a relaxed condition.
• Then HCO3 will enter the RBC, as HCO3 comes in the RBC
Chloride ion will released into the plasma i.e. chloride shift
• The H+ which released from Hb will go and bind with HCO3
_
and form H2CO3.

9. • Now the H2CO3 will dissociate into CO2 and H2O.
• Then the CO2 is released out of RBC into the plasma and
from there it will be exhaled.