I think most of you know something about the sort of architecture and normal structure of a cell and the components within it and the chapter, Chapter 5, has a good description of that for those of you want a refresher.

我想大部分同学都知道一些细胞的,结构组成和构成成分,想回顾一下的同学,可以看下第五章,描述的很详细

耶鲁公开课 - 生物医学工程探索课程节选

It's encased within a membrane, a cell membrane which we talked about the structure of.

都是膜包围细胞器,我们刚讲过其结构的那种膜

耶鲁公开课 - 生物医学工程探索课程节选