shape will dictate the function of the protein. The primary structure is the sequence of Protein folding is the process by which a chain of amino acids forms its final shape. This amino acids bound together by the peptide bonds. The primary structure folds into two common secondary structures, the alpha-helix and beta-pleated sheets. The tertiary structure forms when the R groups of the amino acids begin to interact, further folding and twisting the secondary structures into a 3D shape. Tertiary structures can sometimes be the final structure of a functional protein. However, some proteins form quaternary structures when two or more tertiary structures (now called subunits) combine to fold together into a final active protein. 1. Below, are images of 3 of the 4 protein structures. a. Draw in the two shapes commonly associated with the secondary structure in the space provided. peptide bond Primary Structure Secondary Structure CH-S PHO CH LCH H LCH H Tertiary Structure CH HC CH NH3+ Quaternary Structure 2. Using the images above: * a. What bond types occur in the secondary structure of a protein? hydrogen bonas b. What bond types occur in the tertiary structure of a protein? hydrogen, ionic, c. What bond types occur in the quaternary structure of a protein?