Contents |
| Essential | Nonessential |
|---|---|
| Isoleucine | Alanine |
| Leucine | Asparagine |
| Lysine | Aspartic Acid |
| Methionine | Cysteine* |
| Phenylalanine | Glutamic Acid |
| Threonine | Glutamine* |
| Tryptophan | Glycine* |
| Valine | Proline* |
| Selenocysteine* | |
| Serine* | |
| Tyrosine* | |
| Arginine* | |
| Histidine* |
| Amino acid derivative | Pharmaceutical application |
|---|---|
| 5-HTP (5-hydroxytryptophan) | Experimental treatment for depression.[51] |
| L-DOPA (L-dihydroxyphenylalanine) | Treatment for Parkinsonism.[52] |
| Eflornithine | Drug that inhibits ornithine decarboxylase and is used in the treatment of sleeping sickness.[53] |
| Amino Acid | 3-Letter[86] | 1-Letter[86] | Side chain polarity[86] | Side chain charge (pH 7.4)[86] | Hydropathy index[87] | Absorbance λmax(nm)[88] | ε at λmax (x10−3 M−1 cm−1)[88] |
|---|---|---|---|---|---|---|---|
| Alanine | Ala | A | nonpolar | neutral | 1.8 | ||
| Arginine | Arg | R | polar | positive | −4.5 | ||
| Asparagine | Asn | N | polar | neutral | −3.5 | ||
| Aspartic acid | Asp | D | polar | negative | −3.5 | ||
| Cysteine | Cys | C | nonpolar | neutral | 2.5 | 250 | 0.3 |
| Glutamic acid | Glu | E | polar | negative | −3.5 | ||
| Glutamine | Gln | Q | polar | neutral | −3.5 | ||
| Glycine | Gly | G | nonpolar | neutral | −0.4 | ||
| Histidine | His | H | polar | positive(10%), neutral(90%) | −3.2 | 211 | 5.9 |
| Isoleucine | Ile | I | nonpolar | neutral | 4.5 | ||
| Leucine | Leu | L | nonpolar | neutral | 3.8 | ||
| Lysine | Lys | K | polar | positive | −3.9 | ||
| Methionine | Met | M | nonpolar | neutral | 1.9 | ||
| Phenylalanine | Phe | F | nonpolar | neutral | 2.8 | 257, 206, 188 | 0.2, 9.3, 60.0 |
| Proline | Pro | P | nonpolar | neutral | −1.6 | ||
| Serine | Ser | S | polar | neutral | −0.8 | ||
| Threonine | Thr | T | polar | neutral | −0.7 | ||
| Tryptophan | Trp | W | nonpolar | neutral | −0.9 | 280, 219 | 5.6, 47.0 |
| Tyrosine | Tyr | Y | polar | neutral | −1.3 | 274, 222, 193 | 1.4, 8.0, 48.0 |
| Valine | Val | V | nonpolar | neutral | 4.2 |
| Ambiguous Amino Acids | 3-Letter | 1-Letter |
|---|---|---|
| Asparagine or aspartic acid | Asx | B |
| Glutamine or glutamic acid | Glx | Z |
| Leucine or Isoleucine | Xle | J |
| Unspecified or unknown amino acid | Xaa | X |
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[[File:|thumbnail|200px|The general structure of an α-amino acid, with the amino group on the left and the carboxyl group on the right.]]
In biology and biochemistry, Amino acids are seen as the building blocks of proteins. There are 20 standard amino acids that almost all proteins are made out of. Some amino acids are glycine, alanine, and tryptophan. In chemistry, an amino acid can refer to any molecule that contains both amine and carboxyl functional groups. In biochemistry, this term refers to alpha-amino acids with the general formula H2NCHRCOOH, were R is one of many side groups side group.
Different alpha amino acids are exactly the same except for their R groups. R groups come in many different sizes. Some are as small as a single hydrogen atom (as in glycine), and other R groups are as large as an indole functional group (as in tryptophan). Amino acids are needed to stay alive and do many different things to keep things alive. One very important thing that amino acids do is that they make proteins, which are very long chains of amino acids. Every protein is has its own sequence of amino acids, and that sequence makes the protein have different shapes. Amino acids are like the alphabet for proteins, even though you only have a couple of letters, if you connect them you can make many different words.
Here are sentences from other pages on Amino acid, which are similar to those in the above article.
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