Tryptophan Set type / Edit
«Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a non-polar aromatic amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Tryptophan is also a precursor to the neurotransmitterserotonin, the hormonemelatonin and vitamin B3. It is encoded by the codon UGG.
Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–NH3+; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO−; pKa = 2.38).» (wikipedia)