Page # 4

5. Basic amino acids (side chain with nitrogenous basic group)

Note:* Amino acids with an asterisk are essential amino acids, that must be supplemented through diet.| At pH = 7, Asp and Glu have a net negative charge and exist as anions. At pH = 7, Lys and Arg have a

net positive charge and exist as cations. Rest of the amino acids at this pH exist in the neutral form.

| Structurally, in cystine, the two cysteine molecules are joined through sulfur (disulfide linkage).@@ Proline is an -imino acid.@ Except Glycine all other amino acids are optically active.

NAME

Lystine*

Arginine*

Histidine*

ABBREVIATIONS

Lys(K)

Arg(R)

His(H)

STRUCTURAL FORMULAE ISOELECTRICPOINT[pI]

9.7

10.8

7.6

Page # 2

(3) LIST OF SOME VERY COMMON AMINO ACIDS FOUND IN PROTIENS

NAME

@Glycine

Alanine

Valine*

Leucine*

Isoleucine*

Methionine*

@@Proline

Phenylalanine*

Tryptophan*

ABBREVIATIONS

Gly(G)

Ala(A)

Val(V)

Leu(L)

Ile(I)

Met(M)

Pro(P)

Phe(F)

Trp(W)

STRUCTURAL FORMULAE

22333

CHCOCHCHCH||

HNCH

2233

CHCOCHSCHCH|

HN

1. Neutral amino acids (with nonpolar side chains)ISOELECTRICPOINT[pI]

6.0

6.0

6.0

6.0

6.0

5.7

6.3

5.5

5.9