Classification based on the side chain group

CLASSIFICATION BASED ON THE SIDE CHAIN GROUP

  • These are amino acids, having no functional groups attached to the aliphatic side chain. Eg: glycine, alanine, valine, leucine and isoleucine.
  • The amino acid valine, leucine and isoleucine contain branched aliphatic side chains. Hence, they are also known as branched chain amino acids. 

Simple amino acid

Hydroxyl amino acids

  • These are amino acids containing hydroxyl group in the side chain. Eg: serine and threonine.

Hydroxyl amino acid

Sulphur containing amino acids

  • These are amino acids, containing a sulphur atom attached on the aliphatic side chain. Eg: cysteine, cystine and methionine. 

Sulphur_containing_AA

Acidic amino acids

  • These amino acids will have one more carboxyl group attached on the side chain. Eg: aspartic acid and glutamic acid.

Acidic_amino_acid

Basic amino acids

  • These amino acids will have some nitrogen containing basic group attached on the side chain. Eg: lysine and arginine.

Basic aminoacids

Aromatic amino acids

  • These are amino acids containing the benzene nucleus attached on the side chain.
  • Eg: phenylalanine, tyrosine and tryptophan. The nucleus present in tryptophan is known as indole. Presence of aromatic amino acids like tyrosine and tryptophan in protein, proteins absorb light at a wave length of 280nm

Aromatic amino acid

Heterocyclic amino acids

  • These amino acids contain a ring, which is having one atom other than carbon atom. E.g.: histidine, proline and hydroxyproline.
  • The proline and hydroxyproline are also called as imino acids, because they contain an imino group instead of an amino group, as found in other amino acids.

Heterocyclic aminoacids 

Aminoacid derivatives

  • Amino acid derivatives are formed as an intermediate in the metabolic reactions.
  • Eg: asparagine and glutamine derived from aspartic acid and glutamic acid respectively.

Amino acid derivatives


Last modified: Thursday, 17 November 2011, 11:05 AM