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
Ammonia from brain is removed as: 
Select and explain. 
A. Urea, B. Alanine, C. Glutamate, D. Glutamine
D: Glutamine
Answer: D: Glutamine 
Explanation: Ans: D. Glutamine(Ref. Harper 30/e p292).Ammonia from brain is removed as glutamine.Ammonia disposal:Ammonia from all over body reaches liver, detoxified to urea by liver cells & excreted through kidney.Ammonia formed in most tissues including brain is trapped by glutamate to form glutamine (primary ammonia trapping).