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Nitrogen gas is an industrial gas produced by the fractional distillation of liquid air, or by mechanical means using gaseous air (pressurised reverse osmosis membrane or pressure swing adsorption). Nitrogen gas generators using membranes or pressure swing adsorption (PSA) are typically more cost and energy efficient than bulk-delivered ...
Nitrogen is a fundamental chemical component of amino acids, the molecular building blocks of protein. As such, nitrogen balance may be used as an index of protein metabolism. [1] When more nitrogen is gained than lost by an individual, they are considered to have a positive nitrogen balance and be in a state of overall protein anabolism.
The total nitrogen content of organic matter is mainly formed by the amino groups in proteins. The Total Kjeldahl Nitrogen ( TKN ) is a measure of nitrogen widely used in the analysis of (waste) water, soil, food, feed and organic matter in general.
The difficulty in purifying proteins impeded work by early protein biochemists. Proteins could be obtained in large quantities from blood, egg whites, and keratin, but individual proteins were unavailable. In the 1950s, the Armour Hot Dog Company purified 1 kg of bovine pancreatic ribonuclease A and made it freely available to scientists. This ...
The amount of nitrogen in a chemical substance can be determined by the Kjeldahl method. [21] In particular, nitrogen is an essential component of nucleic acids, amino acids and thus proteins, and the energy-carrying molecule adenosine triphosphate and is thus vital to all life on Earth. [20]
This value is known as the "crude protein" content. The use of correct conversion factors is heavily debated, specifically with the introduction of more plant-derived protein products. [20] However, on food labels the protein is calculated by the nitrogen multiplied by 6.25, because the average nitrogen content of proteins is about 16%.
The nitrogen compounds through which excess nitrogen is eliminated from organisms are called nitrogenous wastes (/ n aɪ ˈ t r ɒ dʒ ɪ n ə s /) or nitrogen wastes. They are ammonia, urea, uric acid, and creatinine. All of these substances are produced from protein metabolism.
Equipment for a study of nitrogen fixation by alpha rays (Fixed Nitrogen Research Laboratory, 1926) The dominant industrial method for producing ammonia is the Haber process also known as the Haber-Bosch process. [70] Fertilizer production is now the largest source of human-produced fixed nitrogen in the terrestrial ecosystem.