A is Alanine

Alanine is A. This molecular bead can be used to spell a name, or a secret message, that only a few geeky people can read. The alpha-carbon atom of alanine is bound with a methyl group (-CH3), making it one of the simplest amino acids with respect to molecular structure and also resulting in alanine being classified as an aliphatic amino acid. The methyl group of alanine is non-reactive and is thus almost never directly involved in protein function.