Primary structure: Each
protein has a unique sequence. Primary structure is like a finger print, each
one has a unique structure. Peptide bond (hydrogen bonds)
Secondary structure: Random
coil structure (beta casein, due to high amount of beta proline); Alpha helix
structure (the more frecuent, the residues are oriented towards the exterior
part of the helix); beta sheet structure (More stable).
Tertiary structure: protein
folds again and forms a 3d structure, due to the action of the interactions
Quaternary structure: Oligomeric
structure, polypeptide chain, combined proteins. Due to all different interactions we can create the
complex structure of the protein. 