Describe the primary, secondary and tertiary structure of proteins

The primary structure of a protein involves a sequence of amino acids. This forms a polypeptide chain and there are 20 different amino acids that may contribute to the primary protein structure. The secondary structure of a protein includes its repeated pattern of folding. There are two main patterns of folding of proteins; the alpha helix and the beta pleated sheet. The alpha helix is characterised by the polypeptide chain coiling in a clockwise manner. On the other hand, the beta pleated sheet involves an interaction of hydrogen bonds to form a twisted structure. Finally, the tertiary structure of a protein alludes to the overall folding of a chain of polypeptides. This is due to interactions between amino acids, the formation of disulphide bridges, and other bonds. This allows a 3D structure to be created, which is unique to a specific protein.