1- gas transport part 2

Question 1

what are the 3 different ways carbon dioxide is transported in blood?

Answer 1

1. in solution (10%)
2. as bicarbonate (60% = main way)
3. as carbamino compounds (30%)

Question 2

how does carbon dioxide travel in solution?

Answer 2

by henry’s law = amount of gas dissolved in liquid is proportional to partial pressure of gas in equilibrium with liquid

CO2 is 20% more soluble than O2

Question 3

how is bicarbonate formed in blood? how does CO2 get carried as it?

Answer 3

in red blood cell:CO2 reacts with water in presence of carbonic anhydrase to form carbonic acid which dissociates into bicarbonate ion and hydrogen ion, hydrogen ions buffered by haemoglobin so pH maintained. the bicarbonate ions are transported out of red blood cells into plasma (in exchange for Cl-, chloride ions) and are carried in plasma to lungs

Question 4

what are carbamino compounds?

Answer 4

• combination of CO2 with terminal amine group in blood proteins
• especially globin of haemoglobin to give carbamino-haemoglobin

Question 5

what is the haldane effect?

Answer 5

RemovingO2from Hb increases the ability of Hb to pick-upCO2and CO2generatedH+

(reduced haemoglobin can bind more CO2 than oxidised haemoglobin)

Question 6

when does haemoglobin have less affinity to bind oxygen?

Answer 6

when giving oxygen to tissues = because oxygen haemoglobin dissociation curve shifts to right at tissues i.e. less affinity to bind to oxygen due to bohr effect

Question 7

what happens with CO2 at lungs?

Answer 7

At the lungs, the haemoglobin pick up oxygen = this weakens ability to bind CO2 and H+