Question

Tertiary structure of proteins having amino acid cysteine is achieved through

• A. Ionic bonds
• B. Covalent bonds
• C. Disulphide bonds
• D. Hydrogen bonds

Answer 1

Answer: (C)

Disulphide bonds

Cysteine are the amino acids which links to form a polypeptide chain. The polypetides are linked together by several covalent bonds which helps in the folding of molecule to attain a tertiary structure. The folded peptide chain are stabilized by chemical bonds. Hydrogen bond, ionic bond, disulphide linkage and hydrophobic interaction stablizes the structure. Disulfide bonds in proteins are formed between the thiol groups of cysteine residues by the process of oxidative folding.

So, the correct answer is option C.