Section 5.9: Allosteric Enzymes

The allosteric properties of enzymes allow them to function somewhat akin to transistors in the chemical control systems of the cell
This capability for control derives from the ability of a small molecule to bind to the enzyme, as an input that involves only a very small amount of energy
The consequence of binding, or output, is to effect the catalytic activity of the enzyme, which typically involves much greater energies
This 'switching' effect of allosteric interaction results from the conformational changes that occur on binding. Such changes can occur both on single-subunit enzymes, and more commonly, on multisubunit complexes where the relative positions and orientations between subunits are altered on binding
The allosteric activity of an enzyme can be seen from its kinetics, where the velocity curve is typically sigmoidal in nature (non-Michaelis-Menten kinetics)