This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
Protein folding is done by: 
Select and explain. 
A. Chaperone, B. Endoplasmic reticulum, C. Peroxisome, D. Lysosome
A: Chaperone
Answer: A: Chaperone 
Explanation: Ans (a) ChaperoneRef; Harper's Biochemistry, 26th ed. pg. 36-37* Chaperone proteins participate in the folding of over half of mammalian proteins. The hsp70 (70-kDa heat shock protein) family of chaperones binds short sequences of hydrophobic amino acids in newly synthesized polypeptides, shielding them front solvent.