Super optional structures

There are super optional structures, which are a mix of the alpha helices and beta sheets (Fig. 24.2). Tertiary structures are three-dimensional structures of the optional structure and amino acids. The accompanying outline (Fig. 24.3) demonstrates the folding of a polypeptide chain, illustrating the progressive system of the protein structure from the essential structure or amino acid sequence through the auxiliary structure and the tertiary structure (Dill et al., 1995). 

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