A human has thousands and thousands of different proteins, each with a specific structure and function. Along with their diverse functions, they vary in structure, each protein having its own unique three-dimensional shape. Proteins are polymers of amino acids joined together by peptide bonds. There are 20 different amino acids to make up all the different proteins on the earth. Each of the amino acids is composed of a central carbon bonded to a hydrogen, a carboxyl group, an amino acid group, and an R-group (Bowen, 2002). The R-group is what distinguishes one amino acid from another. All proteins share three levels of structure, known as primary, secondary, and tertiary structure. A fourth level, quaternary structure, exists when a protein consists of two of more polypeptide chains …show more content…
59). The primary structures are the proteins sequence of amino acids. The amino acids are arranged in a linear arrangement. The secondary structures are the areas of coiling or folding within a protein. The coils or folds are results of hydrogen bonds between the repeating constituents of the polypeptide backbone. Two main types of secondary structure include the α helix, a coil held together by hydrogen bonding between every fourth amino acid and the β pleated sheet, two or more segments of the polypeptide chain lying side by side are connected by hydrogen bonds between parts of the two parallel segments of polypeptide backbone. The tertiary structure is the overall shape of a polypeptide resulting from interactions between the R-groups. Each unique shape of each protein gives it a specific function. The different structures are what mainly affects the protein’s shape. However, the protein’s structure also depends on the protein’s environment. If the pH, salt concentration, temperature, etc. is altered, the weak chemical bonds and interactions within protein may be destroyed, causing the protein to unravel and lose its shape (Urry, Cain , Wasserman, Minorsky,