Representative ketones, from the left: acetone, a common solvent ; Oxaloacetic acid | oxaloacetate, an intermediate in the Krebs Cycle | metabolism of sugars ; acetylacetone in its ( mono ) enol form ( the enol highlighted in blue ); cyclohexanone, precursor to Nylon ; muscone, an animal scent ; and tetracycline, an antibiotic.

Oxaloacetic acid ( also oxalacetic acid ) is an organic compound with the chemical formula C < sub > 4 </ sub > H < sub > 4 </ sub > O < sub > 5 </ sub > or HOOC -( C = O )-( CH < sub > 2 </ sub >)- COOH.

# REDIRECT Oxaloacetic acid

Image: Oxaloacetic acid. png | Oxaloacetic acid

CAM plants store the mostly in the form of malic acid via carboxylation of phosphoenolpyruvate to oxaloacetate, which is then reduced to malate.

Pineapple carries out CAM photosynthesis, fixing carbon dioxide at night and storing it as the acid malate and then releasing it during the day, aiding photosynthesis.

The is stored as the four-carbon acid malate, and then used during photosynthesis during the day.

One is found in the mitochondrial matrix, participating as a key enzyme in the citric acid cycle that catalyzes the oxidation of malate.

Because malate dehydrogenase is closely tied to the citric acid cycle, regulation is highly dependent on TCA products.

The and convention for amino acid configuration refers not to the optical activity of the amino acid itself, but rather to the optical activity of the isomer of glyceraldehyde from which that amino acid can, in theory, be synthesized (- glyceraldehyde is dextrorotary ;-glyceraldehyde is levorotatory ).

The synthesis and characterization of elemental chlorine occurred in 1774 by Swedish chemist Carl Wilhelm Scheele, who called it " dephlogisticated muriatic acid air ," having thought he synthesized the oxide obtained from the hydrochloric acid.

They used a cell-free system to translate a poly-uracil RNA sequence ( i. e., UUUUU ...) and discovered that the polypeptide that they had synthesized consisted of only the amino acid phenylalanine.

Fatty acids, or fatty acid residues when they form part of a lipid, are a diverse group of molecules synthesized by chain-elongation of an acetyl-CoA primer with malonyl-CoA or methylmalonyl-CoA groups in a process called fatty acid synthesis.

Sphingolipids are a complicated family of compounds that share a common structural feature, a sphingoid base backbone that is synthesized de novo from the amino acid serine and a long-chain fatty acyl CoA, then converted into ceramides, phosphosphingolipids, glycosphingolipids and other compounds.

Prenol lipids are synthesized from the five-carbon-unit precursors isopentenyl diphosphate and dimethylallyl diphosphate that are produced mainly via the mevalonic acid ( MVA ) pathway.

Polyketides are synthesized by polymerization of acetyl and propionyl subunits by classic enzymes as well as iterative and multimodular enzymes that share mechanistic features with the fatty acid synthases.

The doubly unsaturated fatty acid linoleic acid as well as the triply unsaturated α-linolenic acid cannot be synthesized in mammalian tissues, and are therefore essential fatty acids and must be obtained from the diet.

Humans and other mammals have a dietary requirement for certain essential fatty acids, such as linoleic acid ( an omega-6 fatty acid ) and alpha-linolenic acid ( an omega-3 fatty acid ) because they cannot be synthesized from simple precursors in the diet.

Serotonin is synthesized from tryptophan by tryptophan hydroxylase, and then further by aromatic acid decarboxylase.

Artificial nucleic acid analogs have been designed and synthesized by chemists, and include peptide nucleic acid, morpholino-and locked nucleic acid, as well as glycol nucleic acid and threose nucleic acid.

Pyrimidines are synthesized first from aspartate and carbamoyl-phosphate in the cytoplasm to the common precursor ring structure orotic acid, onto which a phosphorylated ribosyl unit is covalently linked.

Douglass prepared his sample of Af by thermal decomposition of aqueous chromic acid at 300 - 325-degrees-C.

Two metabolites ( 1, and 2 ) ) of p-aminobenzoic acid ( PABA ) which act as cofactors for the hydroxylation of aniline by acid-fast bacteria are biosynthesized from Aj.

Both theories easily describe the first reaction: CH < sub > 3 </ sub > COOH acts as an Arrhenius acid because it acts as a source of H < sub > 3 </ sub > O < sup >+</ sup > when dissolved in water, and it acts as a Brønsted acid by donating a proton to water.

The numerical value of K < sub > a </ sub > is equal to the concentration of the products divided by the concentration of the reactants, where the reactant is the acid ( HA ) and the products are the conjugate base and H < sup >+</ sup >.

The aromatic and irritating fumes emitted by burning amber are mainly due to this acid.

Baltic amber is distinguished by its yield of succinic acid, hence the name succinite.

He validated his theory by converting carbon disulfide, in several steps, to acetic acid ( 1843 – 45 ).

* Nucleic acid thermodynamics, includes the annealing of DNA or RNA pairing by hydrogen bonds to a complementary sequence, forming a double-stranded polynucleotide

Casein based glues are made by precipitating casein from milk protein using the acetic acid from vinegar.

Since 1998, Harvard University wraps some of the valuable statues on its campus, such as this " Harvard Bixi | Chinese stele ", with waterproof covers every winter, in order to protect them from erosion caused by acid rain.

Antacids either directly neutralize acidity, increasing the pH, or reversibly reduce or block the secretion of acid by gastric cells to reduce acidity in the stomach.

Antacids are taken by mouth to relieve heartburn, the major symptom of gastroesophageal reflux disease, or acid indigestion.

* from reaction of a triphenylphosphinyl ester with an acid halide, a Wittig reaction accompanied by dehydrohalogenation

Since Lavoisier's knowledge of strong acids was mainly restricted to oxoacids, such as ( nitric acid ) and ( sulphuric acid ), which tend to contain central atoms in high oxidation states surrounded by oxygen, and since he was not aware of the true composition of the hydrohalic acids ( HF, HCl, HBr, and HI ), he defined acids in terms of their containing oxygen, which in fact he named from Greek words meaning " acid-former " ( from the Greek οξυς ( oxys ) meaning " acid " or " sharp " and γεινομαι ( geinomai ) meaning " engender ").

According to Liebig, an acid is a hydrogen-containing substance in which the hydrogen could be replaced by a metal.

The Arrhenius definition of acid – base reactions is a development of the hydrogen theory of acids, devised by Svante Arrhenius, which was used to provide a modern definition of acids and bases that followed from his work with Friedrich Wilhelm Ostwald in establishing the presence of ions in aqueous solution in 1884, and led to Arrhenius receiving the Nobel Prize in Chemistry in 1903 for " recognition of the extraordinary services ... rendered to the advancement of chemistry by his electrolytic theory of dissociation ".

As defined by Arrhenius, acid – base reactions are characterized by Arrhenius acids, which dissociate in aqueous solution to form hydrogen ions (), and Arrhenius bases, which form hydroxide () ions.

A common example is nitric acid produced by electric discharge in the atmosphere such as lightning.

Carbonic acid is formed by the reaction

Trees killed by acid rain