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: Biochemistry
Glycine is useful in all of the following, except: 
Select and explain. 
A. Purine synthesis, B. Creatine synthesis, C. Heme synthesis, D. Synthesis of spermine
D: Synthesis of spermine
Answer: D: Synthesis of spermine 
Explanation: CREATININE is Synthesized from 3 Amino Acids (Glycine, Arginine and Methionine) In Heme; Succinyl CoA + Glycine produces Heme In the liver and erythroid precursor cells. C4, C5, N7 of Purine ring is contributed by Glycine, Remember glycine is not contuibute to Pyrimidine Ring. The precursor for synthesis of spermine is the amino acid ornithine.