College Answer

Marks were awarded for the two components of this question – structure and function. The structure component was often only briefly described with a cursory overview provided; however, this component contributed around half of the available marks. Many candidates were unable to accurately describe the structural components of the haemoglobin molecule. The functional component was handled better – however much time was wasted with detailed drawings of the oxyhemoglobin curve (not many marks awarded for this). The basic function of haemoglobin carriage of oxygen and carbon dioxide was known, but detail was often missing about its role as a buffer or its role in the metabolism of nitric oxide.

Discussion