Nitrogen cycle

organic compound containing both amino and acidic functional groups, important in biology

Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and agriculturally important family of flowering plants. It includes trees, shrubs, and perennial or annual herbaceous plants, which are easily recognized by their fruit (legume) and their compound, stipulate leaves. The family is widely distributed, and is the third-largest land plant family in number of species, behind only the Orchidaceae and Asteraceae, with about 765 genera and nearly 20,000 known species.

Urea, also called carbamide (because it is a diamide of carbonic acid), is an organic compound with chemical formula . This amide has two amino groups (−) joined by a carbonyl functional group (−C(=O)−). It is thus the simplest amide of carbamic acid.

Nitrate is a polyatomic ion with the chemical formula . Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble (inorganic) nitrate is bismuth oxynitrate.

chemical compound

chemical compound

300px|thumb|The nest of the Peruvian booby is made of almost pure guano. thumb|Human-made Bird Island (Namibia)|Guano Island near [[Walvis Bay in Namibia]] Guano (Spanish from ) is the accumulated excrement of seabirds or bats. Guano is a highly effective fertiliser due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. Guano was also, to a lesser extent, sought for the production of gunpowder and other explosive materials.

end product of nucleic acid degradation

biogeochemical cycle by which nitrogen is converted into various chemical forms

chemical compound

The nitrite ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name nitrite also refers to organic compounds having the –ONO group, which are esters of nitrous acid.

process which converts nitrogen from the air into compounds such as ammonia

chemical compound

amino acid that cannot be synthesized de novo by the organism

Dutch microbiologist (1851–1931)

cycle of biochemical reactions producing urea

right|thumb|300px|Nitrogen cycle

Ukrainian microbiologist (1856-1953)

thumb|320px|Nitrogen cycle.

Cyanamide is an organic compound with the formula CN2H2. This white solid is widely used in agriculture and the production of pharmaceuticals and other organic compounds. It is also used as an alcohol-deterrent drug. One isomer of the molecule features a nitrile group attached to an amino group. Derivatives of this compound are also referred to as cyanamides, the most common being calcium cyanamide (CaCN2).

thumb|150px|Structure of the nitrosamino group

amino acid that is incorporated biosynthetically into proteins during translation

Nitrogenases are enzymes () that are produced by certain bacteria, such as cyanobacteria (blue-green bacteria) and rhizobacteria. These enzymes are responsible for the reduction of nitrogen (N2) to ammonia (NH3). Nitrogenases are the only family of enzymes known to catalyze this reaction, which is a step in the process of nitrogen fixation. Nitrogen fixation is required for all forms of life, with nitrogen being essential for the biosynthesis of molecules (nucleotides, amino acids) that create plants, animals and other organisms. They are encoded by the Nif genes or homologs. They are related

plant part

chemolithotrophic organism(s)

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thumb|upright=1.35|Leghemoglobin A from a soybean (PDB: 1BIN)

amino acids that can be converted into glucose through gluconeogenesis

thumb|220px|A bioreactor containing the anammox bacterium Kuenenia stuttgartiensis

Diazotrophs are organisms capable of nitrogen fixation, i.e. converting the relatively inert diatomic nitrogen (N2) in Earth's atmosphere into bioavailable compound forms such as ammonia. Diazotrophs are typically microorganisms such as bacteria and archaea, with examples being rhizobia and Frankia and Azospirillum. All diazotrophs contain iron-molybdenum or iron-vanadium nitrogenase systems, and two of the most studied systems are those of Klebsiella pneumoniae and Azotobacter vinelandii due to their genetic tractability and their fast growth.

thumb|right|Root nodules, each containing billions of Rhizobiaceae bacteria

type of amino acid

urea nitrogen in blood

process of converting organic compounds into nitroso derivatives

nutrient deficiency

environmental impact of agricultural and industrial nitrogen

bacteria using nitrate and nitrite as a terminal electron acceptor

plants hosting N-fixing Frankia symbioants in nodules

Assimilate nitrogen from inorganic nitrogen

chemical compound

UAN is a solution of urea and ammonium nitrate in water used as a fertilizer. The combination of urea and ammonium nitrate has an extremely low critical relative humidity (18% at 30 °C) and can therefore only be used in liquid fertilizers. The most commonly used grade of these fertilizer solutions is UAN 32.0.0 (32%N) known as UN32 or UN-32, which consists of 45% ammonium nitrate, 35% urea and only 20% water. Other grades are UAN 28, UAN 30 and UAN 18. The solutions are quite corrosive towards mild steel (up to per year on C1010 steel) and are therefore generally equipped with a corrosion inhi

Functions of nitric oxide in organisms

Nitrogenous compounds found in living systems

type of injection fertilization