A human cell shown here on the opposite side has these formed organelles that I talked about a minute ago, mitochondria, Golgi, endoplasmic reticulum, nucleus.

另一边展示的是人类细胞,它带有我一分钟前讲过的成形的细胞器,线粒体,高尔基体,内质网,细胞核

耶鲁公开课 - 生物医学工程探索课程节选

The nucleotide has a directionality, there's an up and a down to it and it's going to turn out the chain that's formed by polymerizing these has a directionality as well and that's important in defining the structure.

核苷酸有方向性,有上端和下端,核苷酸长链,是由核苷酸沿一个特定方向聚合而成的,这在定义结构时很重要

耶鲁公开课 - 生物医学工程探索课程节选