Protein Tertiary and Quaternary Structure

Protein Structure

Tertiary Structure

• Refers to the 3D shape of a single polypeptide chain, including the interactions between side chains and the folding of the chain
• Determined by the sequence of amino acids, hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bonds
• Stabilizing forces that contribute to the tertiary structure include:
  • Hydrophobic interactions between non-polar amino acids
  • Ionic bonds between charged amino acids
  • Hydrogen bonds between polar amino acids
  • Disulfide bonds between cysteine residues

Quaternary Structure

• Refers to the arrangement of multiple polypeptide chains (subunits) in a protein
• Subunits are held together by:
  • Hydrophobic interactions between non-polar amino acids
  • Ionic bonds between charged amino acids
  • Hydrogen bonds between polar amino acids
  • Disulfide bonds between cysteine residues
• The specific arrangement of subunits determines the protein's biological function

Explore the three-dimensional shape and multiple folded subunit arrangement in proteins through this quiz. Learn about the stabilizing forces and bonding interactions between amino acids that contribute to the tertiary structure, as well as the arrangement of multiple folded protein subunits in quaternary structure.