Some proteins can be switched from an 'off' position

一些蛋白质可以从关闭状态的
where they don't do anything

无所作为
to an 'on' position where they now do something

到成为开启状态后执行某种功能
by only a chemical reaction like this where a phosphorous is added.

中间只发生了一个引入磷酸基的化学反应
Kinases can, in many cases,

激酶能够在很多情况下
serve as a mechanism for switching a protein on or switching a protein off.

能够激活一种蛋白或者关闭一种蛋白
If that protein is an enzyme then you've

如果这种蛋白是一种酶的话
and you've switched it from an 'off' position

你就能够将酶从无催化作用的静息态
where it's not catalyzing a reaction to an 'on' position where it is,

激活至能催化反应的激活态
you've changed the biochemical state of the cell,

你改变了细胞的生化状态
you've changed the chemical reactions that can occur within the cell,

也改变了细胞内发生的化学反应
and you've changed its behavior.

改变了细胞的行为