State the different modes of CO2 transport in blood.
State the different modes of CO2 transport in blood.
Carbon dioxide is carried by the blood in three forms.
(i) In Dissolved State Under normal temperature and pressure, about 7% of CO2 is carried by physical solution.
(ii) As Carbamino Compounds CO2 binds directly with Hb to form an unstable compound carbaminocompounds (CO2 Hb) about 23 % CO2 is transported in this form. When pCO2 is high and pO2 is low as in the tissues, more binding of carbon - dioxide occurs whereas, when pCO2 is low and pO2 is high as in alveol as tissue dissociation of CO2 from carbamino - haemoglobin takes place.
HbO2+CO2⇌HbCO2+H++O2
(iii) As Bicarbonate Ions CO2 reacts with water to rorm carbonic acid (H2CO3) in the presence of carbonic anhydrase in RBC. H2CO3 dissociates into hydrogen and bicarbonate ions (HCO−3).
The whole reeaction proceeds as follows
CO2+H2OCarbonic⇌AnhydraseH2CO3Carbonic acidH2CO3Carbonic acid⇌H+Hydrogenion+HCO−3Bicarbonateion
The carbonic anhydrase reaction mainly occur in RBC as it contain high concentration of enzyme carbonic anhydrase and minute quantity of it is present in plasma too.
Carbon dioxide is carried by the blood in three forms.
(i) In Dissolved State Under normal temperature and pressure, about 7% of CO2 is carried by physical solution.
(ii) As Carbamino Compounds CO2 binds directly with Hb to form an unstable compound carbaminocompounds (CO2 Hb) about 23 % CO2 is transported in this form. When pCO2 is high and pO2 is low as in the tissues, more binding of carbon - dioxide occurs whereas, when pCO2 is low and pO2 is high as in alveol as tissue dissociation of CO2 from carbamino - haemoglobin takes place.
HbO2+CO2⇌HbCO2+H++O2
(iii) As Bicarbonate Ions CO2 reacts with water to rorm carbonic acid (H2CO3) in the presence of carbonic anhydrase in RBC. H2CO3 dissociates into hydrogen and bicarbonate ions (HCO−3).
The whole reeaction proceeds as follows
CO2+H2OCarbonic⇌AnhydraseH2CO3Carbonic acidH2CO3Carbonic acid⇌H+Hydrogenion+HCO−3Bicarbonateion
The carbonic anhydrase reaction mainly occur in RBC as it contain high concentration of enzyme carbonic anhydrase and minute quantity of it is present in plasma too.
