transportation of carbon dioxide

Question 1

how many ways can the carbon dioxide released from respiring tissues be transported?

Answer 1

There are 3 ways in which the carbon dioxide released can transported

Question 2

What happens to 5% of the carbon dioxide released?

Answer 2

5% of carbon dioxide remains as carbon dioxide molecules and is dissolved in the blood plasma until it reaches the lungs

Question 3

what happens to 85% of the carbon dioxide released?

Answer 3

85% of the carbon dioxide diffuses into the erythrocyte and binds with water
this binding is catalysed by carbonic anhydrase
CO2 + H2O –> H2CO3
H2CO3 carbonic acid
carbonic acid - H2CO3 is unstable and therefore immediately breaks down –> HCO3 - + H+

Question 4

where do the products of carbonic acid dissociation end up?

Answer 4

the HCO3- is carried to the lungs
the H+ ions combine with haemoglobin
this combining of the H+ and haemoglobin:
H+ + Hb –> HHB haemoglobin acid
The H+ ions diffuse into haemoglobin and bind to the haem group forcing the oxygen off the haem group in order to allow the dissociation of te oxygen

Question 5

What diffuses into the erythrocytes to balance their negative charge?

Answer 5

to balance the negative charge of the erythrocytes, chloride ions diffuse into the erythrocytes as the hydrogen carbonate ions diffuse out
‘chlorine shift’

Question 6

What happens to 10% of the carbon dioxide?

Answer 6

10% of the carbon dioxide diffuses straight into erythrocyte and combines with haemoglobin
CO2 + Hb –> carbaminohaemoglobin