Naturally-occurring amino acids
Amino acids in living organisms are all α-amino acids (so
called because the amino group is attached to the first carbon atom after the
one in the –COOH group. They all have
the following general structure:
The alkyl group (-R) is
what makes each of the twenty natural amino acids individual.
|
Symbol |
Amino acid |
Skeletal formula |
R-group |
Origin of name |
|
|
Alanine |
|
-CH3 |
From German Alanin from aldehyde + -an + -ine |
|
Arg |
Arginine |
|
-C3H6NHC(NH2)=NH |
From German Arginin perhaps from Greek
arginoeis =
bright-shining or white |
|
Asn |
Asparagine |
|
-CH2CONH2 |
Asparagus + -ine because the
vegetable asparagus
contains it |
|
Asp |
Aspartic acid |
|
-CH2COOH |
From French apartique from Latin asparagus from Greek asparagos |
|
Cys |
Cysteine |
|
-CH2SH |
From cystine + -eine from Greek kustis = bladder
(because it was first isolated from
urine salts) |
|
Gln |
Glutamine |
|
-C2H4CONH2 |
Blend of glutamic acid and amine |
|
Glu |
Glutamic acid |
|
-C2H4COOH |
From gluten + amine + ic |
|
Gly |
Glycine |
|
-H |
From Greek glukus = sweet |
|
His |
Histidine |
|
-CH2C3H4N2 (the ring is
called imidazole) |
From Greek histos = web or tissue + ide + ine |
|
Ile |
Isoleucine |
|
-CH(C2H5)CH2 |
Isomer of
leucine |
|
Leu |
Leucine |
|
-CH2CH(CH3)2 |
From Greek leukos = white |
|
|
Lysine |
|
-C4H8NH2 |
Possibly
related to lysis or lysergic
acid |
|
Met |
Methionine |
|
-C2H4SCH3 |
From methyl + Greek theion = sulphur |
|
Phe |
Phenylalanine |
|
-CH2Ph |
From phenyl + alanine |
|
Pro |
Proline |
|
-C3H6- (the ring joins
the α-amino
group – it’s called a
pyrrolidine ring) |
A contracted
form of pyrrolidine-2-carboyxlic acid |
|
Ser |
Serine |
|
-CH2OH |
From Latin sericum = silk |
|
Thr |
Threonine |
|
-CH(CH3)OH |
From the name
of a sugar called threose |
|
Trp |
Tryptophan |
|
-CH2C8H5N (the two-ring
part is called
indole) |
From tryptic = related to trypsin +
Greek phainein = to appear from trypsin, a protease that is secreted
by the pancreas and acts in
the small intestine from Greek trypsis = friction from Greek tribein = to rub because
trypsin was first obtained by
rubbing down the pancreas with
trypsin |
|
Tyr |
Tyrosine |
|
-CH2PhOH |
From Greek turos = cheese |
|
Val |
Valine |
|
-CH(CH3)2 |
From valeric acid which is a
liquid fatty acid present
is some plant oils. From valerian, a plant and a drug obtained
from the plant |
