This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Leucine is a aminoacid with a 
Select and explain. 
A. Nonpolar side chain, B. Polar side chain, C. Negatively charged side chain, D. Positively charged side chain
A: Nonpolar side chain
Answer: A: Nonpolar side chain 
Explanation: Leucine is non-polar amino acid, i.e. its side chain (R) is nonpolar.