What are the three groups of atoms that make up amino acids called

H, -NH2 and -COOH groups

Explanation:

Lets take the example of simplest amino acid i-e Glycine

It has four functional groups:

1- H-atom

2- -NH2 amino group

3- -COOH carboylic group

4 -R group

Every amino acids have same H ,-NH2 and -COOH groups. The difference is in -R groups.

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