Alanine
Alanine is a hydrophobic amino acid often abbreviated to Ala or A. It is a non-polar amino acid. It has a side chain of -CH3 making it the second simplest amino acid with the codons are GCA, GCC, GCG and GCU.
See single letter amino acid codes
References
1. Berg J., Tymoczko J. and Stryer L (2012) Biochemistry, seventh edition, Basinstoke: W.H.Freeman and Company.