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: Surgery
An alpha helix of a protein is most likely to be disrupted if a missense mutation introduces the following amino acid within the alpha helical structure: 
Select and explain. 
A. Alanine, B. Tyrosine., C. Aspaic acid, D. Glycine
B: Tyrosine.
Answer: B: Tyrosine. 
Explanation: * The alpha helix is disrupted by introduction of following amino acids. 1. Proline - Most common 2. Charged amino acids like H - Histidine A - Aspaic acid A - arginine G - Glutamic acid Ly-Iysine 3. Amino acids with bulky side chains if present in large number eg - (a) Tryptophan (b) Valine (c) Isoleucine