how is CO2 transported in our blood stream ??

 

Does it dissolve in water in blood plasma physically to form dissolve CO2 ??

 

or

 

dissolve in water in blood plasma chemically to form carbonic acid !!

Both. However, for oxygen, it is mainly in the form of oxyhaemoglobin.

A considerable part of dissolved carbon dioxide is converted into carbon acid.

I would say it is the hydrogencarbonate ion that is responsible for the transport.

Mostly in the form of bicarbonate ions. In such form, it serves as a buffer, keeping the body's pH where it should be. Deviations from the body's pH can, in some cases, be fixed by simply exhaling more CO2, lowering the bicarbonate ion concentration.

 

Mokele

Carbon dioxide and carbonic acid exist in an equlibrium in your body, with the equilibrium favouring carbonic acid. The enzyme carbonic anhydrase catalyses the reversible reaction of carbon dioxide to carbonic acid, and vice versa. In tissues where there's carbon dioxide being produced, in order to maintain the equilibrium carbon dioxide is converted to carbonic acid, catalysed by carbonic anhydrase. In the lungs the carbon dioxide is released, so the carbonic acid is converted to carbon diozide to maintain the equilibrium.

the catalysis takes place in the erythrocyte only !?!

 

how about in the plasma where carbonic anhydrase is absent!!!

i think the carbon dioxide is first entered the erythrocytes and be changed to hydrogencarbonate then is released back to plasma.

thats the point !!!

 

so that means that carbon dioxide dissolve physically in blood plasma

but

Co2 form HCO3- in erythrocyte only ??!?!?!?!

 

pleasee... i need arguments !!!!

its present in both. if the plasma was the only medium for transport then we would die (insufficient). fact

 

haemoglobin is actually effected by CO2 conc so that the bohr shift can exist

 

look up the bohr shift