Alanine
Proline
Cysteine
Aspartic Acid
Alkyl Aromatic Neutral Acidic Basic Essential Non-Essential
Glycine
Valine
Glutamine
Glutamic Acid
Isoleucine
Phenylalanine
Serine
Arginine
Leucine
Tryptophan
Threonine
Histidine
Methionine
Asparagine
Tyrosine
Lysine
Ala A
NH2: 9.87 COOH: 2.35
Note: The NH2 and COOH values listed below are pKa values.
Pro P
NH2: 10.60 COOH: 1.99
Cys C
NH2: 10.78 COOH: 1.71
Asp D
NH2: 9.60 COOH: 1.88
Gly G
NH2: 9.60 COOH: 2.34
Val V
NH2: 9.72 COOH: 2.29
Gln Q
NH2: 9.13 COOH: 2.17
Glu E
NH2: 9.67 COOH: 2.19
Ile I
NH2: 9.76 COOH: 2.32
Phe F
NH2: 9.24 COOH: 2.58
Ser S
NH2: 9.15 COOH: 2.21
Arg R
NH2: 9.09 COOH: 2.18
Leu L
NH2: 9.60 COOH: 2.36
Trp W
NH2: 9.39 COOH: 2.38
Thr T
NH2: 9.12 COOH: 2.15
His H
NH2: 8.97 COOH: 1.78
Met M
NH2: 9.21 COOH: 2.28
Asn N
NH2: 8.80 COOH: 2.02
Tyr Y
NH2: 9.11 COOH: 2.20
Lys K
NH2: 10.28 COOH: 8.90
Amino Acids Reference Guide
Amino acids are the building blocks of proteins. Approximately 500 of them exist, but only 20 appear
in our genetic code. Those shown below are known as standard amino acids.
Use the following as a reference guide for amino acid names, abbreviations, and structures.
Chart Key
