Utilitarianism In Reptiles Essay

NITROGRN METABOLISM IN ANIMALS:

Excess amino groups of the body are converted into a single excretory end product. The excretory product of bony fishes is ammonia and are therefore called ammonotelic. Their liver releases ammonia into the blood stream which is then sent towards gills which quickly clear it. Terrestrial animals like human beings excrete urea and are called ureotelic. The excretory product of birds and reptiles is uric acid and thus are called uricotelic. Excretion of urea needs large quantity of water. If bird eliminate urea, they would be weighed down by the large volume of water required and thus would not fly. Therefore, they secrete uric acid as their excretory product

In ureotelic animals, excess ammonia is passed to the mitochondria of liver cells and

Ornthine is then carried back in the mitochondrial matrix and the cycle is complete. There are two nitrogens in urea. One nitrogen came from the ammonia produced in the mitochondrial matrix captured in the form of carbamoyl phosphate. The second nitrogen came from the α−amino group of the aspartate substrate in the reaction involving argininosuccinate synthetase. The carbon of the bicarbonate was the sole carbon of urea.

The fumarate that is produced in the arginosuccinate lyase reaction is an intermediate of the TCA cycle. There are many ways by which this fumarate produced in the cytosol is transported across the inner mitochondrial membrane into the mitochondrial matrix

INHERITED DEFICIENCIES IN THE UREA CYCLE:

There are many inherited diseases of the urea cycle that occur by mutations in the genes that encode any enzyme necessary for this cycle The most common among these is an inherited deficiency of ornithine transcarbamylase, which is an enzyme required for the conversion of ornithine to citrulline. It results in increased levels of ammonia which may be so high as to be