Oxaloacetic acid

Oxaloacetic acid

Names
Preferred IUPAC name 2-Oxobutanedioic acid
Other names Oxaloacetic acid Oxalacetic acid 2-Oxosuccinic acid Ketosuccinic acid
Identifiers
CAS Number	328-42-7 Y
3D model ( JSmol )	Interactive image
ChEBI	CHEBI:30744 Y
ChemSpider	945 Y
ECHA InfoCard	100.005.755
EC Number	206-329-8
IUPHAR/BPS	5236
KEGG	C00036 Y
PubChem CID	970
UNII	2F399MM81J Y
CompTox Dashboard (EPA)	DTXSID8021646
InChI InChI=1S/C4H4O5/c5-2(4(8)9)1-3(6)7/h1H2,(H,6,7)(H,8,9) Y Key: KHPXUQMNIQBQEV-UHFFFAOYSA-N Y
SMILES O=C(O)C(=O)CC(=O)O
Properties
Chemical formula	C4H4O5
Molar mass	132.07 g/mol
Density	1.6 g/cm3
Melting point	161 °C (322 °F; 434 K)
Thermochemistry
Std enthalpy of formation (ΔfH⦵298)	-943.21 kJ/mol
Std enthalpy of combustion (ΔcH⦵298)	-1205.58 kJ/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Oxaloacetic acid (also known as oxalacetic acid or OAA) is a crystalline

Biosynthesis

Oxaloacetate forms in several ways in nature. A principal route is upon

Glyoxylate cycle

The

In previous stages acetyl-CoA is transferred from the mitochondria to the cytoplasm where fatty acid synthase resides. The acetyl-CoA is transported as a citrate, which has been previously formed in the mitochondrial matrix from acetyl-coA and oxaloacetate. This reaction usually initiates the citric acid cycle, but when there is no need of energy it is transported to the cytoplasm where it is broken down to cytoplasmic acetyl-CoA and oxaloacetate.

Another part of the cycle requires NADPH for the synthesis of fatty acids.^[5] Part of this reducing power is generated when the cytosolic oxaloacetate is returned to the mitochondria as long as the internal mitochondrial layer is non-permeable for oxaloacetate. Firstly the oxaloacetate is reduced to malate using NADH. Then the malate is decarboxylated to pyruvate. Now this pyruvate can easily enter the mitochondria, where it is carboxylated again to oxaloacetate by pyruvate carboxylase. In this way, the transfer of acetyl-CoA that is from the mitochondria into the cytoplasm produces a molecule of NADH. The overall reaction, which is spontaneous, may be summarized as:

HCO₃^– + ATP + acetyl-CoA → ADP + P_i + malonyl-CoA

Amino acid synthesis

Six essential amino acids and three nonessential are synthesized from oxaloacetate and pyruvate.^[6] Aspartate and alanine are formed from oxaloacetate and pyruvate, respectively, by transamination from glutamate. Asparagine is synthesized by amidation of aspartate, with glutamine donating the NH4. These are nonessential amino acids, and their simple biosynthetic pathways occur in all organisms. Methionine, threonine, lysine, isoleucine, valine, and leucine are essential amino acids in humans and most vertebrates. Their biosynthetic pathways in bacteria are complex and interconnected.

Oxalate biosynthesis

Oxaloacetate produces oxalate by hydrolysis.^[7]

oxaloacetate + H₂O ⇌ oxalate + acetate

This process is catalyzed by the enzyme oxaloacetase. This enzyme is seen in plants, but is not known in the animal kingdom.^[8]

Interactive pathway map

Click on genes, proteins and metabolites below to link to respective articles.[§ 1] [[File: [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] |alt=Glycolysis and Gluconeogenesis edit]] Glycolysis and Gluconeogenesis edit ^ The interactive pathway map can be edited at WikiPathways: "GlycolysisGluconeogenesis_WP534".

Click on genes, proteins and metabolites below to link to respective articles. [§ 1] [[File: [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] [[ ]] |alt=TCACycle_WP78 edit]] TCACycle_WP78 edit ^ The interactive pathway map can be edited at WikiPathways: "TCACycle_WP78".

See also

• Dioxosuccinic acid
• Glycolysis
• Oxidative phosphorylation
• Citric acid cycle

References