Amino Acids Classification and Properties

Vocabulary flashcards covering the five chemical classifications of amino acids, their side chain structures, properties, and specific features based on the lecture notes.

Negatively charged R groups

A class of amino acids containing carboxylate groups in their side chains, consisting of Aspartate and Glutamate.

Aspartic acid / Glutamic acid

The protonated forms of the carboxylate salt amino acids Aspartate and Glutamate.

Positively charged R groups

A group of basic amino acids that can undergo protonation and deprotonation, including Lysine, Arginine, and Histidine.

Lysine

A positively charged amino acid characterized by a long series of methylines, 1 nitrogen, and a terminal amino group at the epsilon position.

Arginine

A positively charged amino acid featuring 3 nitrogens in its side chain structure.

Histidine

A positively charged amino acid containing 2 nitrogens in its ring structure with a $pKa \times 6$ (approximately $6$) that can become protonated.

Polar, uncharged R groups

Amino acids with side chains that interact well with water and can form hydrogen bonds; includes Serine, Threonine, Cysteine, Asparagine, and Glutamine.

Cysteine

A polar, uncharged amino acid with a thiol group capable of forming disulfide bonds.

Aromatic R groups

Amino acids featuring benzene rings that allow for resonance, including Phenylalanine, Tyrosine, and Tryptophan.

UV light absorption of aromatic R groups

A property of aromatic amino acid side chains where they absorb UV light at a wavelength range of $270-280\,nm$.

Nonpolar, aliphatic R groups

Amino acids with side chains composed mainly of carbons and hydrogen, making them nonpolar; includes Glycine, Alanine, Proline, Valine, Leucine, Isoleucine, and Methionine.

Glycine

A nonpolar, aliphatic amino acid with a single hydrogen as its R group, notable for not being chiral.

Leucine and Isoleucine

Nonpolar, aliphatic amino acids that each contain side chains composed of 4 carbons.

Methionine

A nonpolar, aliphatic amino acid whose side chain contains a sulfur atom.