Aspartic+Acid

Aspartic acid is, together with glutamic acid, classified as an acidic amino acid with a pKa of 4.0. Aspartate is pervasive in biosynthesis. As with all amino acids, the presence of acid protons depends on the residue's local chemical environment and the pH of the solution. It will appear to be a colorless crystal. . []
 * Aspartic acid** (abbreviated as **Asp** or **D)** is an α-amino acid with the chemical formula HOOCCH(NH2)CH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as **aspartate**. The L -isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins. Its codons are GAU and GAC.
 * ~ Properties ||
 * Molecular formula || C 4 H 7 NO 4 ||
 * Molar mass || 133.1 g mol −1 ||
 * Appearance || colourless crystals ||
 * Density || 1.7 g/cm 3 ||
 * Melting point || 270°C ||
 * Boiling point || 324°C (decomposes) ||
 * Solubility in water || 4.5 g/L ||

Aspartic acid was first discovered in 1827 by Plisson, derived from asparagine, which had been isolated from asparagus juice in 1806, by boiling with a base. The term "aspartic acid" refers to either of two forms or a mixture of two. Of these two forms, only one, "L-aspartic acid", is directly incorporated into amino acids. The biological roles of its counterpart, "D-aspartic acid" are more limited. Where enzymatic synthesis will produce one or the other, most chemical synthesis will produce both forms, "DL-aspartic acid," known as a racemic mixture.

Aspartate is non-essential in mammals, being produced from oxaloacetate by transamination. It can also be made in the Urea Cycle from Ornithine and Citrulline. In plants and microorganisms, aspartate is the precursor to several amino acids, including four that are essential for humans: methionine, threonine, isoleucine, and lysine. The conversion of aspartate to these other amino acids begins with reduction of aspartate to its "semialdehyde," O2CCH(NH2)CH2CHO. Asparagine is derived from aspartate via transamidation:

=__Dietary Sources__=

Aspartic acid is not an essential amino acid, which means that it can be synthesized from central metabolic pathway intermediates in humans. Aspartic acid is found in:
 * Animal sources involve luncheon meats, sausage meat, wild game
 * Vegetable sources: sprouting seeds, oat flakes, avocado, asparagus, young sugarcane, and molasses from sugar beets.
 * Dietary supplements, either as aspartic acid itself or salts (such as magnesium aspartate)
 * The sweetener aspartame (NutraSweet, Equal, Canderel, etc.)

Forms and nomenclature
The term "aspartic acid" refers to either of [|two forms] or a mixture of two. [|[3]] Of these two forms, only one, " L -aspartic acid", is directly incorporated into amino acids. The biological roles of its counterpart, " D -aspartic acid" are more limited. Where enzymatic synthesis will produce one or the other, most chemical syntheses will produce both forms, " DL -aspartic acid," known as a racemic mixture.