Search results
Results from the WOW.Com Content Network
The structure of the molecule of urea is O=C(−NH 2) 2.The urea molecule is planar when in a solid crystal because of sp 2 hybridization of the N orbitals. [8] [9] It is non-planar with C 2 symmetry when in the gas phase [10] or in aqueous solution, [9] with C–N–H and H–N–H bond angles that are intermediate between the trigonal planar angle of 120° and the tetrahedral angle of 109.5°.
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.
Urease is a naturally occurring enzyme that catalyzes the hydrolysis of urea to unstable carbamic acid. Rapid decomposition of carbamic acid occurs without enzyme catalysis to form ammonia and carbon dioxide. [2] [3] The ammonia will likely escape to the atmosphere unless it reacts with water to form ammonium (NH 4 +) according to the following ...
Ammonia occurs in nature and has been detected in the interstellar medium. In many countries, it is classified as an extremely hazardous substance. [15] Ammonia is produced biologically in a process called nitrogen fixation, but even more is generated industrially by the Haber process. The process helped revolutionize agriculture by providing ...
The urea cycle converts highly toxic ammonia to urea for excretion. [1] This cycle was the first metabolic cycle to be discovered by Hans Krebs and Kurt Henseleit in 1932, [2] [3] [4] five years before the discovery of the TCA cycle. The urea cycle was described in more detail later on by Ratner and Cohen.
The first symptoms of kidney failure are silent. Failing kidneys can’t remove extra fluid from the body, nor can they filter molecules like urea, which can be toxic in high dosages, from the blood.
Liquid fertilizers comprise anhydrous ammonia, aqueous solutions of ammonia, aqueous solutions of ammonium nitrate or urea. These concentrated products may be diluted with water to form a concentrated liquid fertilizer (e.g., UAN). Advantages of liquid fertilizer are its more rapid effect and easier coverage. [24]
Ureases are nickel-containing metalloenzymes of high molecular weight. [3] Ureases are distinct from Urecases are important in degrading avian faecal matter, which is rich in uric acid, the breakdown product of which is urea, which is then degraded by urease as described here. These enzymes catalyze the hydrolysis of urea into carbon dioxide ...