Amino Acid Reference Chart

Amino acids are the building blocks that make up all proteins, polypeptides and peptides. Each amino acid consists of a central carbon, known as the α-carbon, to which an amino group (-NH₂), an acidic carboxyl group (-COOH) and an organic side chain (-R group) are bound. The R group, which differs for each amino acid, will determine its structure, polarity and pH.

Refer to chart below to explore structures, properties and types for each of the 20 standard amino acids.

Amino Acids	Abbr (3)	Abbr (1)	Enzymes	Products	Codon	Class	Hydrophobicity (pH 7)	Freq. in Proteins (max. 10)	pKa	pI	Chemical formula	Molar mass	IUPAC name	Other names	CAS Number	InChI	SMILES	Appearance	Density	Melting point	Solubility in water
Alanine	Ala	A	Alanine Aminotransferase	13803, 13802, 13826, 13825	GCT, GCC, GCA, GCG	Aliphatic	41	7.5	2.34	6.00	C3H7NO2	89.094	Alanine	2-Aminopropanoic acid	338-69-2; 56-41-7; 302-72-7;	InChI=1S/C2H4NH2COOH/c1-2(4)3(5)6/h2H,4H2,1H3,...	O=C(O)C(N)C	white powder	1.424 g/cm3	258 °C (496 °F; 531 K) (sublimes)	167.2 g/L (25 °C)
Arginine	Arg	R	Arginase	-	CGT, CGC, CGA, CGG, AGA, AGG	Basic	-14	5.0	2.17	10.76	C6H14N4O2	174.204	(S)-2-Amino-5-guanidinopentanoic acid	2-Amino-5-guanidinopentanoic acid	7200-25-1; 157-06-2; 74-79-3	InChI=1S/C6H14N4O2/c7-4(5(11)12)2-1-3-10-6(8)9...	NC(CCCNC(N)=N)C(O)=O	White crystals	1.5±0.1 g/cm3	260 °C; 500 °F; 533 K	14.87 g/100 mL (20 °C)
Asparagine	Asn	N	Asparagine Synthetase; Asparaginase	-	AAT, AAC	Amidic	-28	4.5	2.02	5.41	C4H8N2O3	132.119	Asparagine	2-Amino-3-carbamoylpropanoic acid	70-47-3	InChI=1S/C4H8N2O3/c5-2(4(8)9)1-3(6)7/h2H,1,5H2...	O=C(N)CC@HC(=O)O	white crystals	1.543 g/cm3	234 °C (453 °F; 507 K)	2.94 g/100 mL
Aspartic acid	Asp	D	Aspartic Protease; Aspartic Proteinase	13828, 13827, 13480	GAT, GAC	Acidic	-55	5.0	1.88	2.77	C4H7NO4	133.103	2-Aminobutanedioic acid	Aminosuccinic acid; Asparagic acid; Asparagini...	617-45-8; 56-84-8; 1783-96-6	InChI=1S/C4H7NO4/c5-2(4(8)9)1-3(6)7/h2H,1,5H2,...	O=C(O)CC(N)C(=O)O	colourless crystals	1.7 g/cm3	270 °C (518 °F; 543 K)	4.5 g/L
Cysteine	Cys	C	Cysteine Protease; Cysteine Peptidase	-	TGT, TGC	Sulfur-containing	49	2.0	1.96	5.07	C3H7NO2S	121.150	Cysteine	2-Amino-3-sulfhydrylpropanoic acid	52-90-4; 52-89-1	InChI=1S/C3H7NO2S/c4-2(1-7)3(5)6/h2,7H,1,4H2,(...	C(C@@HN)S	white crystals or powder	1.3±0.1 g/cm	240 °C (464 °F; 513 K) decomposes	soluble
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References

This online resource may be cited as follows

MLA	"Quest Database™ Amino Acid Reference Chart." AAT Bioquest, Inc., 10 Oct. 2025, https://www.aatbio.com/data-sets/amino-acid-reference-chart-table.
APA	AAT Bioquest, Inc. (2025, October 10). Quest Database™ Amino Acid Reference Chart. AAT Bioquest. https://www.aatbio.com/data-sets/amino-acid-reference-chart-table.
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