AMINO ACIDS

Glycine (G)

R-group: H; nonpolar; achiral

Alanine (A)

R-group: methyl; nonpolar

Valine (V)

R-group: isopropyl (think shape); nonpolar

Leucine (L)

R-group: isobutyl; nonpolar

Isoleucine (I)

R-group: sec-butyl; nonpolar; second asymmetric carbon so can make diastereomers

Methionine (M)

R-group: thioether; nonpolar

Proline (P)

R-group: propyl that connects with 2 primary amine to make pentagon; nonpolar

Phenylalanine (F)

R-group: alanine + phenyl; nonpolar aromatic

Tryptophan (W)

R-group: indole group (memorize); nonpolar aromatic

Serine (S)

R-group: CH2 + hydroxyl; polar uncharged

Threonine (T)

R-group: second primary hydroxyl; polar uncharged; second asymmetrical carbon (alongside Ile)

Asparagine (N)

R-group: amide (which includes carbonyl); polar uncharged

Glutamine (Q)

R-group: CH2 + amide; polar uncharged

Tyrosine (Y)

R-group: CH2 + phenol; polar uncharged; pkR = 10.5 (acid at ph=7)

Cysteine (C)

R-group: CH2 + thiol; polar uncharged; pkR = 8.5 (acid at ph=7); can form disulfide bonds (cystine)

Lysine (K)

R-group: 4 x CH2 + NH3+; polar positive charge; pkR = 10.5 (acid at ph=7)

Arginine (R)

R-group: 3 x CH2 + guanidino group (memorize); polar positive charge; pkR = 12.5 (acid at ph=7)

Histidine (H)

R-group: CH2 + imidazole group (memorize); polar positive charge; pkR = 6.0 (base at ph=7)

Aspartic Acid (D)

R-group: CH2 + carboxylate; polar negative charge; pkR = 4.0 (base at ph=7)

Glutamic Acid (E)

R-group: 2 x CH2 + carboxylate; polar negative charge; pkR = 4.0 (base at ph=7)

Which AA can form Diastereomers

isoleucine and threonine

Which AA have pkR and what are they

7 total; Tyrosine (polar uncharged) - 10.5

Cysteine (polar uncharged) - 8.5

Lysine (polar positive) - 10.5; acidic at ph 7

Arginine (polar positive) - 12.5; acidic at ph 7

Histidine (polar positive) - 6.0; basic at ph 7

Aspartic Acid (polar negative) - 4.0; basic at ph 7

Glutamic Acid (polar negative) - 4.0; basic at pH 7