Allosteric binding site Often called allosteric control, allostery is a fundamental biological occurrence relevant to signal transduction pathways, metabolic activities, and genomic transcription ( ). A localised variation in conformation at the active site results from the fast change in the conformational ensemble balance at an allosteric site ( ). Potential disturbances cover the interplay between localised chemical changes ( ) and small molecules/ions. Thus, allostery is the primary way to regulate the function of biological macromolecules (Figure ). Controlling protein activity is done by attaching parts of the protein not in the active site, the "orthosteric" site. The figure shows allosteric inhibition, which happens when a ligand binds to an allosteric site and causes a conformational change on the protein's orthosteric side to inhibit binding. In contrast, allosteric activation (right) occurs when a ligand attaches to an allosteric site, rearranging the protein's orthosteric site structure that enhances its activity. Allosteric regulatory mechanisms are of utmost importance in the context of cellular signalling and the regulation of enzymes.