Carbamoyl phosphate synthetase, function

The liver also receives some ammonia via the portal vein from the intestine, from the bacterial oxidation of amino acids. Whatever its source, the Nib generated in liver mitochondria is immediately used, together with C02 (as HCO3) produced by mitochondrial respiration, to form carbamoyl phosphate in the matrix (Fig. 18-1 la see also Fig. 18-10). This ATP-dependent reaction is catalyzed by carbamoyl phosphate synthetase I, a regulatory enzyme (see below). The mitochondrial form of the enzyme is distinct from the cytosolic (II) form, which has a separate function in pyrimidine biosynthesis (Chapter 22). 

Rubio V. Structure-function studies in carbamoyl phosphate synthetases. Biochem Soc transactions 1993 21 198-202. 

Different strokes. Human beings contain two different carbamoyl phosphate synthetase enzymes. One uses glutamine as a substrate, whereas the other uses ammonia. What are the functions of the these two enzymes ... 

Distinguish the structural and functional properties of the two isozymes of carbamoyl phosphate synthetase in mammals. 

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