<P> Urea serves an important role in the metabolism of nitrogen - containing compounds by animals and is the main nitrogen - containing substance in the urine of mammals . It is a colorless , odorless solid , highly soluble in water , and practically non-toxic ( LD is 15 g / kg for rats ) . Dissolved in water , it is neither acidic nor alkaline . The body uses it in many processes , most notably nitrogen excretion . The liver forms it by combining two ammonia molecules ( NH ) with a carbon dioxide ( CO ) molecule in the urea cycle . Urea is widely used in fertilizers as a source of nitrogen and is an important raw material for the chemical industry . </P>
<P> Urea serves an important role in the metabolism of nitrogen - containing compounds by animals and is the main nitrogen - containing substance in the urine of mammals . It is a colorless , odorless solid , highly soluble in water , and practically non-toxic ( LD is 15 g / kg for rats ) . Dissolved in water , it is neither acidic nor alkaline . The body uses it in many processes , most notably nitrogen excretion . The liver forms it by combining two ammonia molecules ( NH ) with a carbon dioxide ( CO ) molecule in the urea cycle . Urea is widely used in fertilizers as a source of nitrogen and is an important raw material for the chemical industry . </P>
where does urea come from in the body
where does urea come from in the body
The liver
The liver