In a general sense, there are four levels when it comes to deciding the structure of the proteins. There is the primary level, secondary level, tertiary, and quaternary level of the structure. There are different purposes and roles for every single one of the protein structures. In the case of secondary structures, the main idea is for the creation of the three-dimensional form of the proteins. Some common elements of the secondary structure of protein include the alpha helices and the beta-sheets. The secondary structure is formed due to the creation of different hydrogen bonds between the carbonyl oxygen compound and the amide hydrogen compound present.