TRANSPORT OF CARBON DIOXIDE

Question 1

3 ways co2 is transported

Answer 1

• in plasma (5%)
• as HCO3- (85%)
• bound to hb as carboamino-haemoglobin (10%)

Question 2

steps of co2 diffusion (8)

Answer 2

• co2 diffuses in rbc
• carbonic anhydrase catalyses CO2 + water to carbonic acid
• carbonic acid readily dissociates into H+ and HCO3- ions
• HCO3- diffuse out of rbc into plasma
• To balance outflow of negative ions Cl- ions diffuse in (chloride shift)
• H+ ions cause oxyhb to dissociate into o2 + hb
• H+ combines with hb to make HHb (prevents the blood becoming acidic)
• o2 diffuses out of cells into tissues

Question 3

what is chloride shift?

Answer 3

movement of chloride ions into rbc to balance the charge from diffusing out HCO3-

Question 4

reaction of H+ + Hb.4o2

Answer 4

H+ + Hb.4o2 = HHB + 4o2