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
Which one of the following amino acids is most likely to be found in the transmembrane region of a protein 
Select and explain. 
A. Lysine, B. Arginine, C. Leucine, D. Aspartate
C: Leucine
Answer: C: Leucine 
Explanation: Hydrophobic or Nonpolar amino acids are present in transmembrane region.
Hydrophillic or polar amino acids are present on outer surface of membrane.
Leucine is a hydrophobic a.a. so it lies in transmembrane region.