Chains that are formed by peptide bonds that are linked together are

• A. Polypeptide chains
• B. Disulfide chains
• C. Nucleotide chains
• D. Amino acid chains

Answer: (A)

Peptide bonds link amino acids together, forming a polymeric chain. When many amino acids are connected in this way, the resulting chain is called a polypeptide chain. This term specifically describes a long sequence of amino acids bonded through peptide bonds, which is the fundamental structure that builds proteins (often one or more polypeptide chains folded into a functional form).

Disulfide chains aren’t formed by the peptide backbone itself; they’re connections between sulfur atoms in cysteine residues that help stabilize a protein’s shape. Nucleotide chains refer to DNA or RNA, which are polymers of nucleotides, not amino acids. Saying amino acid chains is a bit imprecise for the polymer formed by peptide bonds; polypeptide chain is the standard term that denotes the chain of amino acids linked by peptide bonds.