Amino Acids

Name: Glycine

3 Letter: Gly

1 Letter G

R Group: H

Charge: Uncharged at pH 7.4

Properties: Small, achiral, aliphatic

Name: Alanine

3 Letter: Ala

1 Letter: A

R Group: CH3

Charge: Uncharged

Properties: Aliphatic, small, nonpolar, hydrophobic

Name: Valine

3 Letter: Val

1 Letter: V

R Group: CH(CH3)2

Charge: Uncharged

Properties: Aliphatic, small, branched, nonpolar

Name: Leucine

3 Letter: Leu

1 Letter: L

R Group: CH2CH(CH3)2

Charge: Uncharged

Properties: Aliphatic, branched, nonpolar

Name: Isoleucine

3 Letter: Ile

1 Letter: I

R Group: CH(CH₃)CH₂CH₃

Charge: Uncharged

Properties: Aliphatic, branched, nonpolar

Name: Proline

3 Letter: Pro

1 Letter: P

R group: (CH2)3 attached to amino N

Charge: Uncharged

Properties: Aliphatic, rigid, cyclic

Name: Methionine

3 Letter: Met

1 Letter: M

R group: CH₂CH₂-S-CH₃

Charge: Uncharged

Properties: Thioether, sulfur-containing, nonpolar

Name: Phenylalanine

3 Letter: Phe

1 Letter: F

R group: CH₂-phenyl

Charge: Uncharged

Properties: Aromatic, hydrophobic

Name: Tyrosine

3 Letter: Tyr

1 Letter: Y

R group: CH₂-phenyl-OH

Charge: Mostly uncharged

Properties: Aromatic, H-bonds, can be phosphorylated

Name: Tryptophan

3 Letter: Trp

1 Letter: W

R group: CH₂-indole (bicyclic)

Charge: Uncharged

Properties: Aromatic, bulky, absorbs UV light

Name: Serine

3 Letter: Ser

1 Letter: S

R group: CH₂OH (alcohol)

Charge: Uncharged

Properties: Polar, H-bonding, can be phosphorylated

Name: Threonine

3 Letter: Thr

1 Letter: T

R group: CH(OH)CH₃ (alcohol)

Charge: Uncharged

Properties: Polar, H-bonding, can be phosphorylated

Name: Cysteine

3 Letter: Cys

1 Letter: C

R group: CH₂SH (thiol)

Charge: Slight charge

Properties: Forms disulfide bonds

Name: Asparagine

3 Letter: Asn

1 Letter: N

R group: CH₂CONH₂ (amide)

Charge: Uncharged

Properties: Polar, H-bonding, cannot ionize under normal conditions

Name: Glutamine

3 Letter: Gln

1 Letter: Q

R group: CH₂CH₂CONH₂ (amide)

Charge: Uncharged

Properties: Polar, H-bonding, Nitrogen carrier

Name: Aspartate

3 Letter: Asp

1 Letter: D

R group: CH₂COO⁻ (carboxylate)

Charge: -1

Properties: Acidic, negatively charged; salt bridges

Name: Glutamate

3 Letter: Glu

1 Letter: E

R group: CH₂CH₂COO⁻ (carboxylate)

Charge: -1

Properties: Acidic, negatively charged; salt bridges

Name: Lysine

3 Letter: Lys

1 Letter: K

R group: (CH₂)₄NH₃⁺ (amine)

Charge: +1

Properties: Basic, positively charged; salt bridges

Name: Arginine

3 Letter: Arg

1 Letter: R

R group: (CH₂)₃-NH-C(=NH₂⁺)-NH₂ (guanidinium)

Charge: +1

Properties: Strongly basic, positively charged; binds negative groups

Name: Histidine

3 Letter: His

1 Letter: H

R group: CH₂-imidazole (heterocyclic ring)

Charge: Slight charge

Properties: Weakly basic; important in enzyme active sites; can gain/lose H⁺