Name 3 possible functions for a membrane protein, and name an example for each.
Enzymatic activity. E.g. ATP synthase found in the inner mitochondrial membrane catalyses the synthesis of ATP. 2) Transport of substances. E.g. Aquaporins are integral membrane proteins that are assembled into tetramers to form hydrophilic pores through which water may pass. 3) Signalling. E.g. The insulin receptor (found in abundance on in the plasma membrane of fat cells and skeletal muscle cells) binds the hormone insulin and signals for the uptake of glucose by these cells after a meal.