In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen bonds. Due to carbon's ability to catenate, millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds, along with a few other exceptions, are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive.
In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among others. Often pyrophosphates are called diphosphates. The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid. The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond, a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P–O–P bond, and which mirrors the nomenclature for anhydrides of carboxylic acids. Pyrophosphates are found in ATP and other nucleotide triphosphates, which are very important in biochemistry.
An acidic oxide is an oxide that either produces an acidic solution upon addition to water, or acts as an acceptor of hydroxide ions effectively functioning as a Lewis acid. Acidic oxides will typically have a low pKa and may be inorganic or organic. A commonly encountered acidic oxide, carbon dioxide produces an acidic solution when dissolved.
An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride being (RC(O))2O. Symmetrical acid anhydrides of this type are named by replacing the word acid in the name of the parent carboxylic acid by the word anhydride. Thus, (CH3CO)2O is called acetic anhydride. Mixed (or unsymmetrical) acid anhydrides, such as acetic formic anhydride (see below), are known, whereby reaction occurs between two different carboxylic acids. Nomenclature of unsymmetrical acid anhydrides list the names of both of the reacted carboxylic acids before the word "anhydride" (for example, the dehydration reaction between benzoic acid and propanoic acid would yield "benzoic propanoic anhydride").
Manganese(VII) oxide (manganese heptoxide) is an inorganic compound with the formula Mn2O7. This volatile liquid is highly reactive. It is a dangerous oxidizer and was first described in 1860. It is the acid anhydride of permanganic acid.
Inorganic pyrophosphatase is an enzyme that catalyzes the conversion of one ion of pyrophosphate to two phosphate ions. This is a highly exergonic reaction, and therefore can be coupled to unfavorable biochemical transformations in order to drive these transformations to completion. The functionality of this enzyme plays a critical role in lipid metabolism, calcium absorption and bone formation, and DNA synthesis, as well as other biochemical transformations.
In enzymology, an ADP-sugar diphosphatase (EC 3.6.1.21) is an enzyme that catalyzes the chemical reaction
In enzymology, a CDP-glycerol diphosphatase (EC 3.6.1.16) is an enzyme that catalyzes the chemical reaction
In enzymology, a dolichyldiphosphatase (EC 3.6.1.43) is an enzyme that catalyzes the chemical reaction
In enzymology, a NAD+ diphosphatase (EC 3.6.1.22) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleoside-diphosphatase (EC 3.6.1.6) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleoside-triphosphatase(NTPase) (EC 3.6.1.15) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleoside-triphosphate diphosphatase (EC 3.6.1.19) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleotide diphosphatase (EC 3.6.1.9) is an enzyme that catalyzes the chemical reaction
In enzymology, an oligosaccharide-diphosphodolichol diphosphatase (EC 3.6.1.44) is an enzyme that catalyzes the chemical reaction
In enzymology, a phosphoribosyl-ATP diphosphatase (EC 3.6.1.31) is an enzyme that catalyzes the chemical reaction
In enzymology, an undecaprenyl-diphosphatase (EC 3.6.1.27) is an enzyme that catalyzes the chemical reaction
Crystal arthropathy is a class of joint disorder that is characterized by accumulation of tiny crystals in one or more joints. Polarizing microscopy and application of other crystallographic techniques have improved identification of different microcrystals including monosodium urate, calcium pyrophosphate dihydrate, calcium hydroxyapatite, and calcium oxalate.
An acid anhydride is a type of chemical compound derived by the removal of water molecules from an acid.
Members of the H+, Na+-translocating Pyrophosphatase (M+-PPase) Family (TC# 3.A.10) are found in the vacuolar (tonoplast) membranes of higher plants, algae, and protozoa, and in both bacteria and archaea. They are therefore ancient enzymes.
