ornithine

(noun)

an amino acid, which acts as an intermediate in the biosynthesis of urea

Related Terms

Examples of ornithine in the following topics:

  • Nitrogenous Waste in Terrestrial Animals: The Urea Cycle

    • The amino acid L-ornithine is converted into different intermediates before being regenerated at the end of the urea cycle.
    • Hence, the urea cycle is also referred to as the ornithine cycle.
    • The enzyme ornithine transcarbamylase catalyzes a key step in the urea cycle.

  • The Incorporation of Nonstandard Amino Acids

    • For example, ornithine and citrulline occur in the urea cycle, which is part of amino acid catabolism.

  • Amino Acid Synthesis

    • Nonstandard amino acids often occur as intermediates in the metabolic pathways for standard amino acids — for example, ornithine and citrulline occur in the urea cycle, part of amino acid catabolism.

  • α-Amino Acids

    • These include ornithine, which is a component of the antibiotic bacitracin A, and statin, found as part of a pentapeptide that inhibits the action of the digestive enzyme pepsin.

  • The Primary Structure of Peptides

    • Cyclic peptides are most commonly found in microorganisms, and often incorporate some D-amino acids as well as unusual amino acids such as ornithine (Orn).