الفهرس Only 14 pages are availabe for public view
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Abstract
Proteins are the most versatile macromolecules in living systems and serve crucial functions in essentially all biological processes. There are four levels of structure, Primary structure is the amino acid sequence. Secondary structure refers to the spatial arrangement of amino acid residues that are nearby in the sequence. The α helix and β strand are elements of secondary structure. Tertiary structure refers to the spatial arrangement of amino acid residues that are far apart in the sequence and to the pattern of disulfide bonds. Quaternary structure refers to the spatial arrangement of subunits and the nature of their interactions.