it's ten to 30 microns let's say instead of one to two microns,

有十到三十微米那么大而不是一两微米
so almost ten times bigger.

几乎大了十倍
One of the reasons why human cells have compartments is

人类细胞有区隔结构的一个原因
because their functions are segregated into regions.

是为了把不同生理功能隔开
The nucleus contains all the DNA,

DNA都在细胞核里
and so the early stages of gene expression, transcription,

所以早期的基因表达转录
happened inside the nucleus

发生在将所有DNA
where all the DNA is.

都包于其中的细胞核中
One of the reasons why you would want to

将细胞功能定位于某个固定区域的
segregate things into certain regions

另一个原因是
is that molecules have to move

生物大分子需要移动
in order to accomplish these things;

以完成某些功能