Hi sunshine 142,

The primary structure is a series of amino acids connected by peptide bonds. The secondary structure is the primary structure held by hydrogen bonds forming either an alpha helice or beta pleated sheet. The tertiary structure is the 3D structure of a protein held by 6 different forces such as ionic bonds, hydrophobic forces, van der waals forces etc. The quaternary structure is made up of protein subunits and have the same forces as tertiary structures.

Hope that helps,

Sandra