Amino acids are the building blocks of proteins and are also used by the cell as neurotransmitters, sources of energy and in a variety of other processes. The a-amino acids all have the same basic structure shown below, where the R-group is the portion that is unique for each amino acid. They are called a amino acids, because an amino group is attached to the carbon next to (alpha to) the carboxylic acid group. The table below contains a list of amino acids, abbreviations, side chain pKA values and complete structures.
|3 letter||1 letter|
1These are pKA values that are commonly found for these side chains when they are part of a protein. The pKA values for these side chains may be quite different for the free amino acid in solution.