The two nitrogen atoms that are incorporated into the urea cycle. The source of the nitrogen is: (A) Glutamate & Aspaate, (B) Aspaate & Arginine, (C) Aspaate & NH3, (D) Glutamate & NH3
Answer is C. Two nitrogen atoms of urea are derived from two different sources, one from ammonia and the other directly from alpha amino group of aspaic acid.Ref: DM Vasudevan - Textbook of Biochemistry, 6th edition, page no: 203