20 Common Amino Acids and their properties

Alanine

A or ala

Hydrophobic / Nonpolar

(small side chain)

Valine

V or val

Hydrophobic / Nonpolar

(small side chain)

Leucine

L or leu

Hydrophobic / Nonpolar

(small side chain)

Proline

P or pro

Hydrophobic / Nonpolar

(amino group part of ring causing rigidity)

Isoleucine

I or ile

Hydrophobic / Nonpolar

Phenylalanine

F or phe

Hydrophobic / Nonpolar and Aromatic

Tyrosine

Y or tyr

Hydrophobic / Nonpolar and Aromatic

Tryptophan

W or trp

Hydrophobic / Nonpolar and Aromatic

Glycine

G or gly

Polar

(smallest amino acid and flexible due to no steric hindrance)

Serine

S or ser

Polar

(hydroxyl group (-OH) can form hydrogen bonds)

Asparagine

N or asn

Polar

(amide group (-NH2) can form hydrogen bonds)

Glutamine

Q or gln

Polar

(amide group (-NH2) can form hydrogen bonds)

Threonine

T or thr

Polar

(hydroxyl group (-OH) can hydrogen bond)

Methionine

M or met

Polar

Cysteine

C or cys

Polar

(sulfhydryl group (-SH) can undergo many chemical reactions)

Aspartic Acid

D or asp

Acidic

(negatively charged at neutral pH)

Glutamic Acid

E or glu

Acidic

(negatively charged at neutral pH)

Arginine

R or arg

Basic

(positively charged at neutral pH)

Lysine

K or lys

Basic

(positively charged at neutral pH)

Histidine

H or his

has an Imidazole ring

Hydrophobic / Nonpolar

Alanine, Valine, Leucine, Isoleucine, and Proline

Hydrphobic/Nonpolar and Aromatic

Phenylalanine, Tyrosine, and Tryptophan

Polar

Glycine, Serine, Asparagine, Glutamine, Threonine, Methionine, and Cysteine

Acidic

Aspartic Acid and Glutamic Acid (have charge of -1 in neutral pH)

Basic

Arginine and Lysine (have charge of +1 in neutral pH)

Other

Histidine

Definition of Aliphatic

having carbon atoms linked in open chains (no rings)

What amino acids are NOT aliphatic (or are cyclic)?

Proline, Phenylalanine, Tyrosine, Tryptophan, and Histidine