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
Which of the following is not involved in synthesis of pyrimidines? 
Select and explain. 
A. Glutamine, B. CO2, C. Aspaic acid, D. Glycine
D: Glycine
Answer: D: Glycine 
Explanation: The pyrimidine synthesis is a similar process than that of Purines(Purines Synthesis). In the de novo synthesis of Pyrimidines, the ring issynthesized first and then it is attached to a ribose-phosphate to for a pyrimidinenucleotide. Pyrimidine rings are assembled from bicarbonate, aspaate, and Ammoni