Question

The tertiary structure of the proteins containing the amino acid cysteine is achieved through

• A. Hydrogen bonds
• B. Disulfide bonds and covalent bonds
• C. Vander Waal's force
• D. Ionic bonds
• E. Covalent bonds only

Answer 1

The correct option is B Disulfide bonds and covalent bonds

Proteins show a hierarchical structure. Primary structure is produced by joining together of amino acids through covalent peptide bonds. The secondary structures (helix and sheets) are formed with the help of hydrogen bonds between different parts of linear chain of amino acids. The tertiary structure is derived from folding of protein chain. Cysteine is sulphur containing amino acid. Cysteine plays a major role in formation of tertiary structure. Two molecules of cysteine may bind together with the help of sulfhydryl groups reacting together to form a disulfide bridge.