1. Primary Structure : It refers to refers to the sequence of amino acids in the polypeptide chain.
2. Secondary Structure : Within the long protein chains there are regions in which the chains are organized into regular structures called Alpha Helix ([tex] \alpha [/tex] - helix ) and Beta - pleated sheets . Hydrogen bond is present in secondary structure.
3. Tertiary Structure : The overall three dimensional structure of polypeptide chain is called Tertiary structure.Hydrogen bonding, ionic bonding, dipole-dipole interactions , Disulfide bonding are present in tertiary structure.
4. Quaternary Structure : The polypetide chain aggregates and the protein contains more than one amino acid chain. This is Quaternary structure. Hydrogen bonding is present in them.
