This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
Protein acts as buffer due to which propey 
Select and explain. 
A. Colloid, B. Basic, C. Acidic, D. Amphipathic (amphoteric in nature)
D: Amphipathic (amphoteric in nature)
Answer: D: Amphipathic (amphoteric in nature) 
Explanation: Most biomolecules are amphipathic; that is, they possess regions rich in charged or polar functional groups as well as regions with hydrophobic character. Proteins tend to fold with the R-groups of amino acids with hydrophobic side chains in the interior. Amino acids with charged or polar amino acid side chains. Ref: Harper's Illustrated Biochemistry, 30E (2015) Pg No 8.