If you were to make that change you would find that the molecule now has completely different biological and chemical properties.

如果要做出这样的变化,你会发现,分子的生物形状,和化学性质完全改变了。

麻省理工公开课 - 化学原理课程节选

And what is the shape, for one more clicker question on ammonia?

那它的形状呢？,再来一道关于氨分子的课堂习题？

麻省理工公开课 - 化学原理课程节选