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
Glutamine in blood acts as 
Select and explain. 
A. NH3 transporter, B. Toxic element, C. Store energy, D. Abnormal metabolite
A: NH3 transporter
Answer: A: NH3 transporter 
Explanation: Glutamine is the major transport form of ammonia.