[问答题]
The image shows oxygen dissociation curves for an adu
+nvkzn:4vv yw;z1,u rlt with sickle cell anaemia
n; zwy+vv,1z k4n v:urfrhi fo,5 9to(jg) )p -2htjhk and an adult without sickle cell anaemia. Sickle cell anaemia is a genetic disease caused by a point mutation in the gene coding for haemoglobin, resulting in the substitution of a single amino acid
)2tfto)o(j fgikjh59,hp-r hin the haemoglobin molecule.
1.1.Identify which oxygen dissociation curve represents a person who has sickle cell anaemia.
1.2.Explain a reason for your answer to part (i).
2.Explain how the structure of normal haemoglobin enables cooperative binding.
3.1.Draw a curve on the graph that represents the oxygen saturation of foetal haemoglobin at different partial pressures of oxygen.
3.2.Some people with sickle cell anaemia continue to express foetal haemoglobin into adulthood, a phenomenon known as foetal haemoglobin persistence. Suggest why people with sickle cell anaemia, who express foetal haemoglobin into adulthood, have less severe symptoms of sickle cell anaemia than those who switch to adult haemoglobin.
4.Explain how intense exercise causes changes to the affinity of haemoglobin for oxygen.
