The first control mechanism is the regulatory response to lactose, which uses an intracellular regulatory protein called the lactose repressor to hinder production of β-galactosidase in the absence of lactose.
Este primeiro mecanismo de control é a resposta regulatoria á lactosa, que utiliza unha proteína reguladora intracelular chamada represor da lactosa para dificultar a produción de β-galactosidase en ausencia de lactosa.