Glycine

Glycine is the simplest of all amino acids. All amino acids have some things in common.

The NH group is called an amino group.

The COOH group is an acid group.

Between these is a carbon atom with at least one hydrogen atom (the one sticking out towards you).

Different amino acids have different atoms or groups connected on top of the central carbon atom. For glycine this group is a single hydrogen atom (marked H in the diagram).