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the sequence of chemical reactions, occurring primarily in the liver, that results in the production of urea; the key reaction is the hydrolysis of l-arginine by arginase to l-ornithine and urea; l-ornithine is then converted to l-citrulline by a carbamoylation reaction, then to l-argininosuccinate by an amination reaction involving l-aspartic acid; finally, a lyase-dependent step generates arginine and fumarate.
See urea cycle.
an amino acid obtained from arginine by the action of the enzyme arginase which also splits off urea; it is an intermediate in urea biosynthesis.
ornithine carbamoyl transferase (OCT), ornithine transcarbamoylase
see ornithine carbamoyl transferase.
alternative name for urea cycle since ornithine is the carrier of the nitrogens.
ornithine decarboxylase test
a means of identifying different members of the Enterobacteriaceae as well as other gram-negative bacteria.
deficiency see gyrate atrophy.