The 3-dimensional shapes of the proteins result from the wrapping and folding of the chain of amino acids due to various interactions between their sidechain groups' physical and chemical characteristics. Proteins as Polymers A. Polymers Polymers are large molecules that are composed of many similar smaller subunits called monomers . The greater the number of different monomers present, the greater the complexity. The greater the amount of branching of the chains within the molecule, the greater the complexity. Proteins are linear and unbranched chains of the 20 amino acids.
Specific proteins have precise lengths and sequences of amino acids.
This enables different proteins to be distinguished from one another, and makes possible the diversity of structure and function found within this important class of compounds. Primary structure of a protein is the sequence of amino acids in the polypeptide chain. It is the same for all molecules of a specific protein. Changing the order of the amino acids in the chain will produce a different protein with a different structure and functionality. Secondary structure of a protein is the local conformation of the polypeptide backbone formed by the bending, coiling and folding of the amino acid chain.