Timberlake uses a simple method of classification,
identifying amino acids as polar or non-polar. A further
subclassification of acidic-polar when the side chain
contains a carboxylic acid, and basic-polar when the side
chain contains an amino group is also introduced.
Devlin classifies amino acids along structural lines
A third method of classification, sourced from Koolman2 .
This classification system is again based on structure of
the side chain.
basically aa's are classified into the following way
2.hydroxy gp containing aa's.eg:Serine,Threonine.
3.sulpher containing aa's.eg:cystine,methionine.
3.acidic aa's.eg:Glutamic acid,Glutamine,
amino acids are of 3 types
now acidity is due to presence of excess cooH grps,
basicity due to excess NH2 grp. neutral has eual no of NH2
and COOH grps
Again it can be classified as essential-eg leucine,lysine
etc and non-essential amino acids.