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
Flexibility of protein depends on: 
Select and explain. 
A. Glycine, B. Tryptophan, C. Phenylalanine, D. Histidine
A: Glycine
Answer: A: Glycine 
Explanation: Ans. A. GlycineGlycine having the smallest R group fit into small spaces and induces bends in the alpha helix.Glycine is usually present in beta turns.Kinks in protein structure is due to proline.