This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Amino Acid Metabolism, Subject name: Biochemistry
For conversion of asparatate to asparagine, nitrogen comes from - 
Select and explain. 
A. Alanine, B. Glutamate, C. Glutamine, D. Histidine
C: Glutamine
Answer: C: Glutamine 
Explanation: Ans. is 'c' i.e., Glutamine o Synthesis of asparagine from aspartate is catalyzed by asparagine synthetase,o Donor of amide group (containing nitrogen) in this reaction is glutamine.