You have seen that most students are able to memorize the levels of structure in a protein--primary, secondary, tertiary, and quaternary. the question now becomes how to aid the students in visualizing and understanding that the sequence of amino acids will impart ionic or hydrogen bonding that will induce curves (alpha-helix) or folds (beta-sheets) in the amino acid chain. these curves and folds will be able to interact amongst each other and give the polypeptide (which is part of a protein or maybe the entire protein being made) a three-dimensional shape that will enable the polypeptide to bind to another polypeptide and form a complete protein.