Amino Acid Memorization

Alanine (Ala A)

Nonpolar / hydrophobic amino acid.

Arginine (Arg R)

Positively charged / basic amino acid. Generally carries a positive charge near physiological pH and can form electrostatic interactions with negatively charged groups.

Asparagine (Asn N)

Polar uncharged amino acid. Can participate in hydrogen bonding.

Aspartate (Asp D)

Negatively charged / acidic amino acid. Its side chain contains an additional carboxyl group that is usually deprotonated and negatively charged near physiological pH.

Cysteine (Cys C)

Polar uncharged and sulfur-containing amino acid. Contains a sulfhydryl group (-SH) and two cysteines can form a covalent disulfide bond (-S-S-).

Glutamine (Gln Q)

Polar uncharged amino acid. Can participate in hydrogen bonding.

Glutamate (Glu E)

Negatively charged / acidic amino acid. Its side chain contains an additional carboxyl group and is usually deprotonated and negatively charged near physiological pH.

Glycine (Gly G)

Nonpolar amino acid with a side chain consisting only of hydrogen. It is the smallest amino acid and increases local backbone flexibility.

Histidine (His H)

Basic amino acid whose side-chain pKa is near physiological pH. Its protonation state can change readily which makes it useful in proton-transfer chemistry and enzyme catalysis.

Isoleucine (Ile I)

Nonpolar / hydrophobic amino acid.

Leucine (Leu L)

Nonpolar / hydrophobic amino acid.

Lysine (Lys K)

Positively charged / basic amino acid. Generally remains protonated and positively charged near physiological pH.

Methionine (Met M)

Nonpolar / hydrophobic and sulfur-containing amino acid. Its sulfur is part of a largely nonpolar side chain.

Phenylalanine (Phe F)

Nonpolar / hydrophobic and aromatic amino acid. It is strongly nonpolar.

Proline (Pro P)

Nonpolar amino acid with a cyclic side chain that connects back to the backbone nitrogen. It is rigid and restricts backbone movement.

Serine (Ser S)

Polar uncharged amino acid. Can participate in hydrogen bonding.

Threonine (Thr T)

Polar uncharged amino acid. Can participate in hydrogen bonding.

Tryptophan (Trp W)

Nonpolar / hydrophobic and aromatic amino acid. Contains nitrogen within its aromatic ring system.

Tyrosine (Tyr Y)

Polar uncharged and aromatic amino acid. Its hydroxyl group gives it additional polar character.

Valine (Val V)

Nonpolar / hydrophobic amino acid.