Amino Acids

1
Amino Acids

• (Chapter 37B)

2
General Structures

• Two contrasting groups
• -COOH acidic
• -NH3 basic
• ?-amino acids
• 20 different ?-amino acids found in protein in
  nature

?
3
Some amino acids
4
Chirality
COO-

• L-amino acid
• Look down at H-C bond, other groups, read
  clockwise (corn law)

C
R
H3N
H
5
Special features

• High m.p. and b.p.
• Glycine (RH) is a solid
• Soluble in water
• High dipole moment
• Less acidic and basic than normal RCOOH and RNH2

6
Amphoteric
7
Isoelectric point
pH at which the concentrations of (II) (III) is
called the isoelectric point.
8
Separating amino acids

• Chromatography

9
Separating amino acids

• Electrophoresis

10
Peptide Linkage
11
Proteins

• Polypeptides
• About 20 amino acids
• Number of possible protein polymers is very large

12
Proteins