amino acids

Amino acids
All proteins are polymers of amino acids. More than 300 different amino acids have been described in nature, only twenty are commonly found as constituents of mammalian Proteins.
Each amino acid (except for proline) has a carboxyl group, an amino group, and a distinctive side chain ("R-group") bonded to the ?-carbon atom.








General structure
Classification of amino acids
1-Based on structure
A-Aliphatic amino acids
a. Mono amino mono carboxylic acids:
. Simple amino acids:
1.Glycine, 2.Alanine






. Branched chain amino acids
3. Valine, 4.Leucine, 5.Isoleucine




. Hydroxy amino acids:
6. Serine, 7.Threonine




. Sulphur containing:
8. Cysteine, 9.Methionine




. Having amide group:
10. Asparagine, 11.Glutamine





b. Mono amino dicarboxylic acids
12. aspartic acid, 13.Glutamic acid





c. Di basic mono carboxylic acids :
14. Lysine, 15.Arginine






B. Aromatic amino acids
16. Phenylalanine, 17.Tyrosine