Nonpolar
Side Chains
alanine (Ala,
A) 
glycine (Gly,
G) 
isoleucine
(Ile, I) 
leucine (Leu,
L) 
methionine
(Met, M) 
phenylalanine
(Phe, F)
proline
(Pro, P) 
tryptophan
(Trp, W) 
valine
(Val, V) 
Polar
Side Chains
asparagine
(Asn, N) 
threonine
(Thr, T) 
serine
(Ser, S) 
glutamine
(Gln, Q) 
Acidic
Side Chains
Basic Side Chains
aspartic
acid (Asp, D)
glutamic
acid (Glu, E)
cysteine
(Cys, C)
tyrosine
(Tyr, Y)
arginine
(Arg, R)
histidine
(His, H)
lysine
(Lys, K)
Each
ionizable functional group is shown in the form predominantly present
at pH 7.