3.2.12 Adult & Fetal Haemoglobin

Question 1

Why is there a dissociation curve?

Answer 1

• Haemoglobin’s affinity for O2 changes depending on the amount of O2 molecules bound to it

Question 2

Explaining shape of curve

Answer 2

• After first O2 molecule binds to haemoglobin the protein undergoes conformational change so the next O2 binds easier (cooperative bonding)
• As haemoglobin becomes more saturated with O2 it becomes harder for last O2 molecule to bind because of shortage of remaining sites

Question 3

Foetal Haemoglobin

Answer 3

• Higher affinity for O2 at lower partial pressures
• Easy uptake and release of O2 in respiring tissue