Answer: Cysteine residues are involved in disulfide bridges that helps to form tertiary structure in a protein
Explanation:
The tertiary structure of a protein will have a single polypeptide chain backbone with protein secondary structures. The interactions and bonds of the side chains within a protein determine its tertiary structure.
The cysteine forms the disulfide bridges and they link the fragments within a polypeptide chain. Sometimes those fragments are located very far from each other with respect to their primary structure. So, the tertiary structure is the three dimensional shape of a protein.
