Well a negative control we learned about from the trp operon.

好，我们从色氨酸操纵子中了解控概念。

And the other thing they'll have in an operon is called an operator.

在操纵子中，另一个重要部分叫做操纵基因。

Positive control example I'll give you is the lac operon.

我给你举一个正控例子是乳糖操纵子。

And the negative control is the trp operon.

控例子是色氨酸操纵子。

And so let's talk about how this works is the lac operon in bacteria because this the first one we really started to understand.

那么，让我们来谈谈这个机制是如何在细菌乳糖操纵子中运作，因为这是我们最先开始理解一个例子。