The 20 Amino Acids of Proteins Flashcards
1
Q
Glycine (Gly or G)
A
Nonpolar side chains; hydrophobic
H
l
H3N+ — C — C — O-
l ll
H O
2
Q
Alanine (Ala or A)
A
Nonpolar side chains; hydrophobic
CH3
l
H3N+ — C — C — O-
l ll
H O
3
Q
Valine (Val or V)
A
Nonpolar side chains; hydrophobic
CH3 CH3
\ /
CH2
l
H3N+ — C — C — O-
l ll
H O
4
Q
Isoleucine (Ileor I)
A
Nonpolar Side Chains; Hydrophobic
CH3
l
CH2
l
H3C — CH
l
H3N+ — C — C — O-
l ll
H O
5
Q
Leucine (Leu or L)
A
Nonpolar side chains; hydrophobic
CH3 CH3
\ /
CH2
l
H3N+ — C — C — O-
l ll
H O
6
Q
Methionine (Met or M)
A
Nonpolar side chains; hydrophobic
CH3
l
S
l
CH2
l
CH2
l
H3N+ — C — C — O-
l ll
H O
7
Q
Phenylalanine (Phe or F)
A
Nonpolar side chains; hydrophobic
*hexagon*
l
CH2
l
H3N+ — C — C — O-
l ll
H O
8
Q
Tryptophan (Trp or W)
A
Nonpolar side chains; hydrophobic
*hexagon*
*half hexagon* — NH
l
CH2
l
H3N+ — C — C — O-
l ll
H O
9
Q
Proline (Pro or P)
A
Nonpolar side chains; hydrophobic
CH2
/ \
H2C CH2
l l
H2N+ — C — C — O-
l ll
H O
10
Q
Serine (Ser or S)
A
Polar side chains; hydrophilic
OH
l
CH2
l
H3N+ — C — C — O-
l ll
H O
11
Q
Threonine (Thr or T)
A
Polar side chains; hydrophilic
OH CH3
\ /
CH
l
H3N+ — C — C — O-
l ll
H O
12
Q
Cysteine (Cys or C)
A
*sometimes classified as a nonpolar amino acid
Polar side chains; hydrophilic
SH
l
CH2
l
H3N+ — C — C — O-
l ll
H O
13
Q
Tyrosine (Tyr or Y)
A
Polar side chains; hydrophilic
OH
l
*hexagon*
l
H3N+ — C — C — O-
l ll
H O
14
Q
Asparagine (Asn or N)
A
Polar side chains; hydrophilic
NH2 O
\ //
C
l
CH2
l
H3N+ — C — C — O-
l ll
H O
15
Q
Glutamine (Gln or Q)
A
NH2 O
\ //
C
l
CH2
l
CH2
l
H3N+ -- C -- C -- O-
l ll
H O
