Haemoglobin and oxygen transportEdexcel International A Level Biology: Mind map

Exam questions on Haemoglobin and oxygen transport

1. A mountaineer climbs from sea level to a camp at 5,000 m, where the partial pressure of oxygen in the air she breathes is about half of its value at sea level.
   Explain how haemoglobin is able to pick up oxygen in the lungs and release it in respiring tissues.2 marks
2. During a marathon, a runner's leg muscle cells respire rapidly and release large amounts of carbon dioxide into the blood.
   Explain how the carbon dioxide released by the muscle cells increases the supply of oxygen to them.2 marks
3. Oxygen passes from a mother's blood to her fetus's blood across the placenta. In the placenta the partial pressure of oxygen is about 3 kPa. At this partial pressure the mother's (adult) haemoglobin is about 45% saturated with oxygen, whereas the fetal haemoglobin is about 65% saturated.
   Explain how the difference in saturation at 3 kPa allows the fetus to obtain enough oxygen from its mother's blood.3 marks