What is an enzyme inhibitor?
An enzyme inhibitor is a molecule that binds to an enzyme's active site, or another site on the enzyme, and blocks the enzyme's catalysis of the reaction. Enzyme inhibitors are generally specific to one enzyme and control that enzyme's activity. They also control essential enzymes such as proteases or nucleases that, if left unchecked, may damage a cell. 

Many poisons produced by animals or plants are enzyme inhibitors, and many drug molecules are enzyme inhibitors that inhibit an aberrant human enzyme or an enzyme critical for the survival of a pathogen. Since anti-pathogen inhibitors generally target only one enzyme, such drugs are highly specific and generally produce few side effects in humans. 

Medicinal enzyme inhibitors often have low dissociation constants, meaning a minute amount of the inhibitor will inhibit the enzyme. The discovery of enzyme inhibitors and their refinement are researched in biochemistry and pharmacology.
O que é um inibidor de enzimas?
Um inibidor de enzimas é uma molécula que se liga ao local ativo de uma enzima, ou outro local na enzima, e bloqueia a catálise da enzima da reação. Inibidores de enzimas são geralmente específicos de uma enzima e controlam a atividade dessa enzima. Eles também controlam enzimas essenciais como proteases ou nucleases que, se não forem controladas, podem danificar uma célula. Muitos venenos produzidos por animais ou plantas são inibidores de enzimas, e muitas moléculas de drogas são inibidores de enzimas que inibem uma enzima humana aberrante ou uma enzima crítica para a sobrevivência de um patógeno.