This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Glycine provides all in purine synthesis except 
Select and explain. 
A. Carbon-4, B. Carbon-5, C. Nitrogen-4, D. Nitrogen-7
C: Nitrogen-4
Answer: C: Nitrogen-4 
Explanation: Amino group of aspaate provide N1 Formyl THFA - C2 Amide N of glutamine - N3 and N9 glycine- C4 C5 C7 respiratory Co2- C6 Methenyl THFA -C8 Ref-Harpers illustrated biochemistry 30/e p849