The secondary structure of protein is determined by

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The secondary structure of a protein refers to the shape in which a long polypeptide chain can exist. They are found to exist in two different types of structures, namely -helix and -pleated sheet structures. These structures arise due to the regular folding of the backbone of the polypeptide chain due to hydrogen bonding between the - C = O and - NH - groups of the peptide bonds. Therefore, the secondary structure of a protein is determined by hydrogen bonds. Answer: hydrogen bond