Question

how many alanine and glutamine need to be metabolized to produce urea, no other amino acid is inteoduced to system is assumption?

Answer 1

To produce urea 1 alanine and 1 glutamine need. Amino group of alanine is transfer to alpha-ketoglutarate by transaminase to produce glutamate, then glutamate dehydrogenase enzyme release amino group from glutamate and produce alpha-ketoglutarate that participate again in transamination. This NH3 molecule participate in urea cycle with bicarbonate and 2 mol ATP in mitochondria.

In urea we can get 2 mol NH3 molecule.one come from alanine and one come from aspartate. Aspartate with citrulline produce arginino succinate which further produce urea by several reaction.