Transport of carbon dioxide Flashcards
How is carbon dioxide transported in the blood?
5% is directly dissolved in the plamsa
10% directly binds to the Hb to make carbaminohemoglobin
85% is transported as hydrogen-carbonate ions
How is carbonic acid made?
Carbon dioxide diffuses into the red blood cells and reacts with water with a carbonic anhydrase enzyme to produce carbonic acid
How are hydrogen-carbonate ions made from the carbonic acid?
A H+ ion is released from the carbonic acid
What happens to the hydrogen-carbonate ions?
They move out of the red blood cell to the plasma
How is the charge of a red blood cell maintained after the loss of the -ve ions?
Chloride ions enter the red blood cell in chloride shift
What happens to the H+ ions in the red blood cell?
They are taken out of the cell and react with haemoglobin to form haemoglobinic acid, where the haemoglobin acts like a buffer to maintain a constant pH
What is the Bohr effect?
It describes the effect that an increasing concentration of carbon dioxide has on haemoglobin.
What is the Bohr shift?
When more CO2 is present, Hb becomes less saturated with O2, which is shown in the dissociation curve that shifts down and right
What is the outcome of the Bohr effect?
The O2 is released where more CO2 is produced in respiration so that the cells can get oxygen to respire.
