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In the stomach there is an increase in pH of the mucosal lining as a result of urea hydrolysis, which prevents movement of hydrogen ions between gastric glands and gastric lumen. [21] In addition, the high ammonia concentrations have an effect on intercellular tight junctions increasing permeability and also disrupting the gastric mucous ...
The soil's pH also has a strong effect on the amount of volatilization. Specifically, highly alkaline soils (pH~8.2 or higher) have proven to increase urea hydrolysis. One study has shown complete hydrolysis of urea within two days of application on such soils. In acidic soils (pH 5.2) the urea took twice as long to hydrolyze. [7]
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 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.
Rapid urease test, also known as the CLO test (Campylobacter-like organism test), is a rapid diagnostic test for diagnosis of Helicobacter pylori. [1] The basis of the test is the ability of H. pylori to secrete the urease enzyme, which catalyzes the conversion of urea to ammonia and carbon dioxide.
Some infections caused by K. aerogenes result from specific antibiotic treatments, venous catheter insertions, and/or surgical procedures. It is generally found in the human gastrointestinal tract and does not generally cause disease in healthy individuals. It has been found to live in various wastes, hygiene chemicals, and soil.
Patients swallow urea labelled with an uncommon isotope, either radioactive carbon-14 (nowadays preferred in many countries) or non-radioactive carbon-13.In the subsequent 10–30 minutes, the detection of isotope-labelled carbon dioxide in exhaled breath indicates that the urea was split; this indicates that urease (the enzyme that H. pylori uses to metabolize urea to produce ammonia) is ...
Biotin, a water-soluble B vitamin, is a bicyclic urea.. In chemistry, ureas are a class of organic compounds with the formula (R 2 N) 2 CO where R = H, alkyl, aryl, etc. Thus, in addition to describing the specific chemical compound urea ((H 2 N) 2 CO), urea is the name of a functional group that is found in many compounds and materials of both practical and theoretical interest.