There are many highly acclaimed researchers, scientists and doctors that doubt or deny that HIV is the cause of aids. Some of them even doubt the mere existence of HIV. If you have severe fear of aids, make sure to take a look at what these people have to say.
From Wikipedia, the free encyclopedia. The urea cycle (also known as the ornithine cycle) is a cycle of biochemical reactions occurring in many animals that produces urea ((NH2)2CO) from ammonia (NH3). This cycle was the first metabolic cycle discovered (Hans Krebs and Kurt Henseleit, 1932), five years before the discovery of the TCA cycle. In mammals, the urea cycle takes place primarily in the liver, and to a lesser extent in the kidney.
Urea Is Formed in the Liver. From these and other facts Krebs and Henseleit deduced that a cyclic process occurs (Fig. 17-10), in which ornithine plays a role resembling that of oxaloacetate in the citric acid cycle. A molecule of ornithine combines with one molecule of ammonia and one of CO2 to form citrulline.