Lesson 1.3. Amino Acid Structure Defintions

Phenylalanine (Phe, F)

has a phenyl ring

Tryptophan (Trp, W)

has an indole ring

Leucine (Leu, L)

has a isobutyl R-group

Isoleucine (Ile, I)

has an sec-butyl R-group

Valine (Val, V)

has an isopropyl R-group

Methionine (Met, M)

has a thioether (RSR’)

Glycine (Gly, G)

has no chiral center

Alanine (Ala, A)

has a methyl R-group

Proline (Pro, P)

has an imino group

Asparagine (Asn, N)

has a 1-C amide R-group

Glutamine (Gln, Q

has 2-C amide R-group

Serine (Ser, S)

has a 1° -OH group

Threonine (Thr, T)

has a 2° -OH group

Tyrosine (Tyr, Y)

has a phenol group

Cysteine (Cys, C)

has a sulfhydryl group

Aspartic Acid (Asp, D)

has a beta-carboxylic acid R-group

Glutamic Acid (Glu, E)

has a gamma-carboxylic acid R-group

Histidine (His, H)

has an imidazole ring

Lysine (Lys, K)

has a 4-C amine R group

Arginine (Arg, R)

Has an guanidino group