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uria cycle
Urea is the chief nitrogenous waste of mammals. It is a nitrogenous waste product with the break down of amino acids. This occurs by deamination.

Deamination of amino acids results in the production of ammonia (NH3). Ammonia is an extremely toxic base and its accumulation in the body would quickly be fatal.
 The liver contains a system of carrier molecules and enzymes which quickly converts the ammonia (and carbon dioxide) into urea.
This is called the urea cycle.
One turn of the cycle:
    consumes 2 molecules of ammonia
    consumes 1 molecule of carbon dioxide
    creates 1 molecule of urea ((NH2)2CO
    regenerates a molecule of ornithine for another turn.
Although our body cannot tolerate high concentrations of urea, it is much less poisonous than ammonia.

Urea is removed efficiently by the kidneys.


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