Describe urea cycle



Urea cycle : (a) It is called Kreb’s Hansleit or Ornithine Cycle.

(b) Urea is formed from ammonia in the mitochondria of liver.
© Urea formation was studied by Kreb’s and Hansleit
in 1932.
(d) One molecule of COz and 2 molecules of NH3 are
required for urea formation.
(e) Various enzymes are also involved in this process
(f) Urea formation is a cyclic chain.
(g) Ornithine combines with C02 and ammonia to form citrulline.
(h) Citrulline reacts with NH3 and HzO and forms arginine.
(i) Arginine is decomposed into urea and ornithine in the presence of Arginase enzyme.
(j) Ornithine again enters in the cycle.