Glycine is the simplest amino acid. It can also be described as aminoethanoic acid or aminoacetic acid.
Like all amino acids, it has an amino group (-NH2) - blue with 2 white balls - at one end, and a carboxylic acid group (-COOH) - grey, connected to red, and red and white - at the other end. Between these is the
α- (alpha) carbon
Its 'R' group is simply a hydrogen, one of the white balls attached to the central carbon atom.
Since there are two hydrogens, there is no asymmetry here, so unlike other amino acids, glycine does not exist in both L- and D- forms (L being almost universal in living organisms).