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CHAPTER 1
BASIC THERMODYNAMIC AND BIOCHEMICAL CONCEPTS
COO
Ϫ
ϩ
H3N
C
H
H
C
CH2
CH3
Isoleucine
(Ile, I)
CH3
COO
Ϫ
ϩ
H3N
C
H
CH 2
CH
CH3
H3C
Leucine
(Leu, L)
COO
Ϫ
ϩ
H3N
C
H
CH
CH 3
H3C
Valine
(Val, V)
COO
Ϫ
ϩ
H3N
C
H
CH 3
Alanine
(Ala, A)
COO
Ϫ
ϩ
H3N
C
H
H
Glycine
(Gly, G)
COO
Ϫ
ϩ H3N
C
H
CH2
C
N
H
CH
Tryptophan
(Trp, W)
COO
Ϫ
ϩ
H3N
C
H
CH2
OH
Tyrosine
(Tyr, Y)
Phenylalanine
(Phe, F)
COO
Ϫ
ϩ
H3N
C
H
CH2
Aliphatic amino acids
Amino acids with aromatic rings
Amino acids with hydroxyl side chains
Positively charged amino acids
COO
Ϫ
ϩ
H3N
C
H
H
C
H
Serine
(Ser, S)
OH
COO
Ϫ
ϩ
H3N
C
H
H
C
CH3
Threonine
(Thr, T)
OH
COO
Ϫ
H3N
C
H
CH2
CH2
CH2
CH2
NH3ϩ
Lysine
(Lys, K)
COO
Ϫ
H3N
C
H
H
CH2
CH2
CH2
N
C
NH2ϩ
NH2
Arginine
(Arg, R)
C
COO
Ϫ
H3N
C
H
CH2
C
Histidine
(His, H)
NH
ϩHN
CH
H
Figure 1.8 The 20 standard amino acids found in proteins.
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