Aminosyrer Flashcards
G
Gly, Glycine
Simplest amino acid
Single hydrogen atom as its side chain
Achiral
Hydrophobic
A
Ala, Alanine
Next simplest amino acid.
Has methyl group (-CH3) as side chain
Hydrophobic
P
Pro, Proline
Aliphatic side chain, where side chain is bonded to both the nitrogen and alpha-carbon atoms, yielding a pyrrolidine ring.
Influences protein architecture.
Hydrophobic
V
Val, Valine
Larger hydrocarbon side chain
Hydrophobic
L
Leu, Leucine
Larger hydrocarbon side chain
Hydrophobic
I
Ile, Isoleucine
Larger hydrocarbon side chain. Includes an additional chiral center
Hydrophobic
M
Met, Methionine
Contains largely aliphatic side chain that includes a thioether (- S -) group.
Hydrophobic
W
Trp, Tryptophan
Indole group joined to a methylene ( - CH2 -) group; comprises two fused rings containing an NH group.
Less hydrophobic bc of side chain NH group.
F
Phe, Phenylalanine
Contains phenyl ring attached in place of one of the hydrogen atoms of alanine
Hydrophobic
S
Ser, Serine
Contain hydroxyl group (-OH) attached to hydrophobic side chain. Makes it more hydrophilic
Polar
T
Thr, Threonine
Contain hydroxyl group (-OH) attached to hydrophobic side chain. Makes it more hydrophilic.
Polar
Y
Tyr, Tyrosine
Contain hydroxyl group (-OH) attached to hydrophobic side chain. Makes it more hydrophilic.
Polar
N
Asn, Asparagine
Terminal carboxamide
Polar
Q
Gln, Glutamine
Terminal carboxamide. Side chain one methylene longer than Asparagine.
Polar
C
Cys, Cysteine
Sulfhydryl, or thiol (-SH) group in place of (-OH). Thiol group much more reactive. Pairs of sulfhydryl groups may come together to form disulfide bonds, which are particularly important in stabilizing some proteins.
Polar
K
Lys, Lysine
Long side chains that terminate with groups that are positively charged at neutral pH.
Capped by a primary amino group.
Hydrophilic
R
Arg, Arginine
Long side chains that terminate with groups that are positively charged at neutral pH.
Capped by a guanidinium group.
Hydrophilic.
H
His, Histidine
Contains an imidazole group, an aromatic ring that can also be positively charged. With a pKa value near 6, it can be uncharged or positively charged near neutral pH, depending on local environment.
Often found in active sites of enzymes, where the ring can bind and release protons in the course of the enzymatic reaction.
Hydrophilic.
D
Asp, Aspartate
Negatively charged at physiological pH.
E
Glu, Glutamate
Negatively charged at physiological pH.
