Asparagine

A reaction between asparagine and reducing sugars or reactive carbonyls produces acrylamide (acrylic amide) in food when heated to sufficient temperature. These products occur in baked goods such as French fries, potato chips, and toasted bread.
 * Asparagine** (abbreviated as **Asn** or **N**; **Asx** or **B** represent either asparagine or aspartic acid ) is one of the 20 most common natural amino acids on Earth . It has carboxamide as the side-chain 's functional group . It is not an essential amino acid . Its codons are AAU and AAC.

Also know simply as Asn, asparagine is a non-essential amino acid that is found in a number of different sources. First identified in 1806, asparagine is also sometimes referred to as aspartic acid. The popular name for the amino acid came about due to the discovery of the compound in asparagus juice. Since that time, the amino acid has been identified in a wide range of foods consumed in just about every culture around the world.

Asparagine has since been found in a number of different animal and plant sources. Some seafood also contains the amino acid, as do poultry and eggs. Dairy products like milk and cheese also contain small amounts of the acid. Even beef is known to contain some amounts of Asn.

[]
 * Molecular formula || C 4 H 8 N 2 O 3 ||
 * Molar mass || 132.12 g mol −1 ||
 * Acidity (p//K// a ) || 2.02 (carboxyl), 8.8 (amino) ||

History
Asparagine was first isolated in 1806, under a crystalline __form__, by French chemists Louis Nicolas Vauquelin and Pierre Jean Robiquet (then a young assistant) from asparagus juice, in which it is abundant — hence, the name they chose for that new matter — becoming the first amino acid to be isolated. The characteristic smell observed in the urine of individuals after their consumption of asparagus is attributed to various metabolic byproducts of asparagine. A few years later, in 1809, Pierre Jean Robiquet again identified, this time from licorice root, a substance with properties he qualified as very similar to those of asparagine, that Plisson in 1828 identified as asparagine itself.

Function
The nervous system requires asparagine. It also plays an important role in the synthesis of ammonia.

Dietary sources
Asparagine is not an __essential amino acid__, which means that it can be synthesized from central metabolic pathway intermediates in humans and is not required in the __diet__. Asparagine is found in:


 * **Animal sources**: dairy, whey , beef , poultry , eggs , fish , lactalbumin , seafood
 * **Plant sources**: asparagus, potatoes , legumes , nuts , seeds , soy , whole grains

Biosynthesis
The precursor to asparagine is oxaloacetate. Oxaloacetate is converted to aspartate using a transaminase enzyme. The enzyme transfers the amino group from gllutanate to oxaloacetate producing [|α-ketoglutarate] and aspartate. The enzyme asparagine synthetase produces asparagine, AMP glutamate, and prophosphate from aspartate, glutamine, and [|ATP]. In the asparagine synthetase reaction, ATP is used to activate aspartate, forming β-aspartyl-AMP. Glutamine donates an ammonium group, which reacts with β-aspartyl-AMP to form asparagine and free AMP.



Degradation
Aspartate is a glucogenic amino acid. [|L-asparaginase] hydrolyzes the amide group to form aspartate and ammonium. A transaminase converts the aspartate to oxaloacetate, which can then be metabolized in the citric acid cycle or gluconeogenesis.