The small molecule causing the conformational change is an allosteric effector .
引起结构变化的小分子叫做变构效应场。
Allosteric site a part of an enzyme to which a specific effector or modulator can be attached .
别构部位：可以结合特定效应物或者调节物的酶的一个部分。
When the product accumulates beyond an optimal amount it binds to a site ( allosteric site ) on the enzyme , changing the shape so that it can no longer react with its substrate .
