Is glycine achiral? [duplicate]








**This question already has answers here**:
 
 




[What is the perfect definition for chirality?](/questions/59124/what-is-the-perfect-definition-for-chirality)

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Closed 6 years ago.



In [this video](https://www.youtube.com/watch?v=DhwAp6yQHQI) (10:20>) the woman says that the Glycine is not *[chiral](https://en.wikipedia.org/wiki/Chirality_(chemistry))* because it has 2 different group only rather than four. 


Then I can understand from her things that *amino acid* can be chiral just in case that it has 4 different groups. But I don't understand why when even it has only two different groups it can not be chiral, here is the group of the left side can be on the right and vice versa and this is an a mirror image as well. 




It is not chiral because If the amino group and the carboxylic acid group changed places, the "new" arrangement would be superimposable on the old arrangement.


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