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
In the first step of Heme synthesis, what is required - 
Select and explain. 
A. Fe, B. Folate, C. Glycine, D. Histidine
C: Glycine
Answer: C: Glycine 
Explanation: Two starting materials of heme synthesis are succinyl-CoA and glycine. Pyridoxal phosphate is also required.