Hint: Nearly \[80\% \] of the nitrogen excreted in humans and mammals is in the form of urea, which is formed by a series of reactions in the cytosol and mitochondrial matrix of liver cells. These reactions are referred to collectively as the urea cycle, the Krebs-Henseleit cycle, or the ornithine cycle. Ammonia is a poisonous by-product of nitrogen metabolism that should be eliminated from our bodies.
Complete answer: The ornithine cycle operates the liver to form urea. In the mitochondria of liver cells, the urea cycle transforms excess ammonia to urea. The liver excretes urea into the bloodstream, where it flows to the kidneys and is eventually excreted in urine. The urea cycle is critical to these species because if nitrogen or ammonia are not removed from the organism, the consequences can be serious. Urea is much less harmful than ammonia and can stay inside the body for a longer period of time without causing any damage.
Additional information: Before the urea cycle begins, ammonia is converted to carbamoyl phosphate. Carbamoyl phosphate synthetase I catalyse the reaction, which involves the use of two ATP molecules. After that, the carbamoyl phosphate joins the urea cycle.
Note: The urea cycle (also known as the ornithine cycle) is a series of biochemical reactions that results in the formation of urea from ammonia. In ureotelic species, this cycle occurs. The urea cycle transforms highly radioactive ammonia to urea, which is then excreted. Urea cycle aims to eliminate the poisonous compound ammonia by converting it to a harmless form known as urea, which is then excreted from the body.