Allósterískur
Allósterískur is an Icelandic adjective meaning allosteric. In biochemistry and molecular biology, an allosteric site is a site on an enzyme or protein other than the active site. When a molecule, known as an allosteric effector, binds to the allosteric site, it changes the shape of the protein. This change in shape can either activate or inhibit the protein's function. Allosteric regulation is a crucial mechanism for controlling metabolic pathways and cellular processes. It allows cells to fine-tune enzyme activity in response to changing conditions. For example, the end product of a metabolic pathway might act as an allosteric inhibitor of an enzyme earlier in the pathway, preventing the overproduction of the product. Conversely, an allosteric activator might bind to an enzyme and increase its catalytic efficiency when more product is needed. This type of regulation is distinct from competitive inhibition, where a molecule competes directly with the substrate for the active site. Allosteric binding is typically reversible, and the effector molecule can dissociate from the protein, returning it to its original state. The concept of allosteric regulation is fundamental to understanding how biological systems maintain homeostasis and respond to stimuli.