Describe protein binding and its significance in pharmacology.

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College Answer

Descriptions of protein binding were generally too brief (e.g. a statement saying that drugs and hormones bind to proteins in the plasma rather than a description of usually reversible binding with a drug-protein equilibrium).

It was expected that the factors which determine protein binding would be described. Marks were attributed if proteins, along with characteristics of the drugs they bind, were named. Candidates achieved better marks if they named the pharmacological parameters affected by protein binding and explained how and why change occurs along with the significance of those changes. Few candidates differentiated between tissue and plasma protein binding and the different effects on the volume of distribution.