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Ornithine
CAS#: 70-26-8
Molecular Structure:

Molecular Formula: C5H12N2O2
Molecular Weight: 132.16
Functional Use:
L-Ornithine is one of the products of the action of the enzyme arginase
on L-arginine, creating urea. Therefore, ornithine is a central part of
the urea cycle, which allows for the disposal of excess nitrogen.
Ornithine is recycled and, in a manner, is a catalyst. First, ammonia is
converted into carbamoyl phosphate (phosphate-CONH2), which creates one
half of urea. Ornithine is converted into a urea derivative at the δ
(terminal) nitrogen by carbamoyl phosphate. Another nitrogen is added
from aspartate, producing the denitrogenated fumarate, and the resulting
arginine (a guanidinium compound) is hydrolysed back to ornithine,
producing urea. The nitrogens of urea come from the ammonia and
aspartate, and the nitrogen in ornithine remains intact |