Introduction: “Proteins are large, complex molecules that play many critical roles in the body” (Genetics Home Reference, 2014, p. xx-xx). “They do most of the work in cells and are necessary for the structure, function, and regulation of the body's tissues and organs” (Genetics Home Reference, 2014, p. xx-xx). “Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to each other in long chains” (Genetics Home Reference, 2014, p. xx-xx). “There are 20 different types of amino acids that can be combined to form a protein” (Genetics Home Reference, 2014, p. xx-xx). “The sequence of amino acids determines each protein's unique three-dimensional structure and its specific function” (Genetics Home Reference, 2014, p. xx-xx). “Proteins are complex molecules made up of carbon, hydrogen, oxygen, and nitrogen (sometimes sulfur and phosphorus)” (TutorVista.com, 2014, p. xx-xx). There are four levels in the structure of proteins: primary structure, secondary structure, tertiary structure and finally quaternary structure. Each structure has a unique shape. “The primary structure of a protein is its sequence of amino acids” (Sadava, 2011, p. 44). polypeptides” (Sadava, 2011, p. 45). The primary structure is composed of one of the strongest bonds, the covalent bonds. The secondary structure is made up of weaker bonds, which are hydrogen bonds forms. Either the alpha helix or the beta pleated sheets. “The helix (alpha) is a right-handed coil that turns in the same direction as a standard wood screw” (Sadava, 2011, p. 46). by hydrogen bonds forming between the δ+ hydrogen of the NH of an amino... middle of paper... onomers take longer to travel along the gel, thus resting in the upper bands, illustrated by Figure 2 and demonstrated by Figure 1.ReferencesGenetics Home Reference (2014, February 10). What are proteins and what do they do? - Reference for the house of genetics. Retrieved from http://ghr.nlm.nih.gov/handbook/howgeneswork/proteinLife Science Core at UCLA, Martin, L., Chen, K., Johnson, L., Foley, R., & Murotake, R. ( 2005 ). Analysis of protein size and subunit composition by SDS-polyacrylamide gel electrophoresis. Los Angeles, CA. Sadava, D. E. (2011). Life: The science of biology (9th ed.). Sunderland, Mass.: Sinauer Associates.TutorVista.com (2014). Proteins, protein composition, protein classification | Tutorvista.com. Retrieved from http://www.tutorvista.com/content/biology/biology-iv/animal-nutrition/proteins.php#