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Located in liver cytosol, it is the fourth enzyme of the urea cycle and involved in the biosynthesis of arginine in all species and the production of urea in ureotelic species. [2] Mutations resulting in low activity of the enzyme increase levels of urea in the body and result in various side effects.
The body uses it in many processes, most notably nitrogen excretion. The liver forms it by combining two ammonia molecules (NH 3) with a carbon dioxide (CO 2) molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry.
Urea produced by the liver is then released into the bloodstream, where it travels to the kidneys and is ultimately excreted in urine. The urea cycle is essential to these organisms, because if the nitrogen or ammonia is not eliminated from the organism it can be very detrimental. [ 5 ]
At birth, the liver comprises roughly 4% of body weight and weighs on average about 120 g (4 oz). Over the course of further development, it will increase to 1.4–1.6 kg (3.1–3.5 lb) but will only take up 2.5–3.5% of body weight. [40] Hepatosomatic index (HSI) is the ratio of liver weight to body weight. [41]
The liver detoxifies and breaks down chemicals, poisons and other toxins that enter the body. For example, the liver transforms ammonia (which is poisonous) into urea in fish, amphibians and mammals, and into uric acid in birds and reptiles. Urea is filtered by the kidney into urine or through the gills in fish and tadpoles. Uric acid is paste ...
The excretion of urea is called ureotelism. Land animals, mainly amphibians and mammals, convert ammonia into urea, a process which occurs in the liver and kidney. These animals are called ureotelic. [3] Urea is a less toxic compound than ammonia; two nitrogen atoms are eliminated through it and less water is needed for its excretion.
It is located in mitochondria of several tissues in the body, with most abundance in the kidney and prostate. It may be found at lower levels in macrophages, lactating mammary glands, and brain. [5] The second isozyme may be found in the absence of other urea cycle enzymes. [4]
Citrullinemia belongs to a class of genetic diseases called urea cycle disorders. The urea cycle is a sequence of chemical reactions taking place in the liver. These reactions process excess nitrogen, generated when protein is used for energy by the body, to make urea, which is excreted by the kidneys.