Question
Biology Question on Human Excretory System
The principal nitrogenous excretory compound in humans is synthesised
in kidneys but eliminated mostly through liver
in kidneys as well as eliminated by kidneys
in liver and also eliminated by the same through bile
in the liver, but eliminated mostly through kidneys.
in the liver, but eliminated mostly through kidneys.
Solution
The principle nitrogenous excretory compound in humans is urea. Urea is produced in a series of reactions (urea cycle) which take place in the mitochondrial matrix and cytosol of liver cells. Urea cycle (ornithine cycle) is the series of biochemical reactions that converts ammonia, which is highly toxic, and carbon dioxide to the much less toxic urea during the excretion of metabolic nitrogen derived from the deamination of excess amino acids. The urea is ultimately excreted in solution in urine.