Within a mammal’s pulmonary circulation, blood with a low oxygen content is oxygenated as red blood cells travel through the alveolar capillaries and haemoglobin in the cells combines with oxygen. The blood then returns to the heart, which pumps it around the systemic circulation.
(a)[5]
Describe the series of events in the heart that enables blood returning in the pulmonary circulation to move into the systemic circulation. You do not need to include details of control of the cardiac cycle.
(b(i))[2]
Fig. 6.1 shows a haemoglobin molecule as a globular molecule. Describe the quaternary structure of a haemoglobin molecule.
(b(ii))[2]
Outline how a haemoglobin molecule can reach full saturation with oxygen to form oxyhaemoglobin.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “blood passes into the heart through the pulmonary vein(s)” …