Biochemistry Definitions and glossary AG

Chemistry term within the framework of the study of the Laigret petroleum process. Definitions by Thierry Saint Germès, November 30, 2008.
Biochemistry definitions from H to Z
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acid: Hydrogenated chemical compound, the dissolution of which in water provides H + ions, and which, therefore, has a set of properties characterizing the acid function.

Acetic acid : Acid to which vinegar owes its flavor and properties. With the formula CH3CO2H, it is the type of organic monoacids of the fatty series. It is the oxidation product of ethyl alcohol with the elimination of water.

= amino acid Amino acid: generic body having both amine and acid, which are the essential materials of living matter.

butyric acid: Normal butyric acid, or butanoic acid, CH3CH2CH2CO2H, found in the glyceride state in butter, is prepared by fermentation of sugar or starch.

oleic acid or ethylenically acid: Of formula CH3 (CH2) 7CH = CH (CH2) 7CO2H, it is formed in the saponification of fatty substances. It can attach two hydrogen atoms to give stearic acid.

acyl: Generic name of RCO radicals - existing in the carboxyl acids.

alkali: Generic name for alkali metal hydroxides and ammonium hydroxide. Marine or mineral alkali, soda, Vegetable alkali, potash, volatile alkali, ammonia.

The alkalis, the main ones being caustic soda NaOH and potash KOH, are very soluble in water; they are strong bases, giving alkaline salts with acids.

alcohol: Generic term designating bodies with the same chemical properties as ordinary alcohol. The term “alcohols” refers to compounds derived from hydrocarbons by substitution of a hydroxyl OH with a hydrogen atom bonded to a saturated carbon. The official nomenclature assigns to alcohols the name of the carbide from which they are derived and in which the final e is replaced by the suffix -ol; numbering is necessary in case of ambiguity.

Eg. CH3OH [methanol]
CH3-CHOH-CH3 [2-propanol]
CH3-CH = CH-CH2OH [butene-ol-2 1]

ethyl alcohol or ethanol: It is often referred to by the name of alcohol, without qualifier. Its formula is CH3CH2OH. It exists in the composition of wines, beers, ciders, eaux-de-vie.

aldehyde: volatile liquid of formula CH3CHO, resulting from the controlled oxidation of alcohol, and prototype of a series of bodies also called aldehydes by analogy.

aliphatic: (Gr. Aleiphar, -Atos, fat). Said organic body open chain.

amide: Generic name of compounds derived from ammonia or from an amine by substitution of acyl radicals for hydrogens.

amine: Generic name of compounds formed by substitution of hydrocarbon radicals univalent to the hydrogen of ammonia.

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ammonia: Gas combination of nitrogen and hydrogen NH3.

ammonium: Name of univalent radical NH4, which acts as alkali metal salts of ammonia.

anhydride: Body whose formula results from that of an oxacid by elimination of water between the hydroxyls.

nitrogen: A simple gaseous body, which constitutes about four-fifths of the air. The nitrogen cycle is the series of transformations through which nitrogen circulates between the mineral, plant and animal kingdoms. It has the chemical formula N. It is the seventh element in the periodic table of the elements.


bacillus: (from Latin: bacillus, small stick) Name given to all bacteria that have the shape of a stick.

bacteria: (from the Greek: baktêria, stick) Name given to a group of unicellular beings, of very simple structure, with a diffuse nucleus, and reproducing by fissiparity. Some bacteria require oxygen (aerobes), others cannot support free oxygen (anaerobes), but many can adapt to the presence or absence of this gas (mixed or facultative anaerobes). Their enzymatic richness gives them an intense biochemical activity. Their proliferation is only possible within certain temperature limits; soil bacteria thrive at room temperature, pathogenic bacteria, between 37 and 40 ° C.

barite: Oxide or barium hydroxide.

barium: (gr. barus, heavy). Alkaline earth metal, analogous to calcium. Barium is element 56, with an atomic mass Ba = 137,36. Reported in 1774 by Scheele, who distinguished barite from lime, it was isolated by Davy in 1808. It is a white metal. It oxidizes in air and breaks down water in the cold. It is bivalent in its compounds, which are very similar to those of calcium. It is only prepared in the laboratory, from its natural sulfate (barite) or its natural carbonate (witherite).

base: chemical body capable of neutralizing an acid by combining with it. The bases are hydroxides, generally metallic, the ionization of which provides OH- ions.

Culture broth: Broth, sterilized, for microorganism culture.

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pitch: Residue from partial evaporation or fractional distillation of oils, tars or other organic matter.

Brome: (gr. brômos, foul odor) Discovered in 1826 by Balard in the mother waters of saline, near Montpellier, bromine is the element 35, of atomic mass Br = 79,92. It is a dark red liquid, with an unpleasant odor, three times denser than water. It is slightly soluble in water (bromine water).

butyrin: Butyric triester of glycerin, one of the constituents of butter.

butyric: Normal butyric or butanoic acid, CH3CH2CH2CO2H, found in the glyceride state in butter, is prepared by fermentation of sugar or starch; it is a thick liquid with a rancid odor.


calcium: (lat. calx, calcis, hot). The most common metal of the alkaline earth group. Isolated by Davy in 1808, calcium is the chemical element 20, with an atomic mass Ca = 40,08. It is a white, soft solid. It oxidizes in the air giving hot hot CaO, and also combines with hydrogen, halogens, nitrogen. Very reducing, it decomposes cold water. It is bivalent in its compounds.

capric: Said of an acid found in butter, which melts at 31 ° C.

caproic: Said of a fatty acid which is found in the form of glyceride (caproin) in butter and coconut oil.

carbonate: Salt or ester of carbonic acid.

carbon: Carbon is the chemical element 6, with atomic mass C = 12,01.

carbonic: Anhydride or carbon dioxide, one of the oxides of carbon, with the formula CO2.

carbide: bit combination of carbon with another element.

carboxyl: Univalent radical CO2H characteristic of organic acids.

Carboxyl or carboxylic acid: Said bodies that contain the carboxyl group.

catalysis: (gr. katalusis, dissolution). Action by which a substance increases the speed of a chemical reaction without appearing to take part in it. Examples of catalysis are very numerous, as are catalysts.

caustic: (Lat causticus;. The gr kaustikos;. Of kaiein, burn). That attack, which corrodes the animal and plant tissues: caustic liquid. caustic soda.

Chaux: (lat. Calx). Calcium oxide CaO, or lively hot, forming the basis of limestone is a refractory white solid. Caustic, quicklime is very greedy for water, which transforms it, with a great release of heat, into slaked or hydrated lime Ca (OH) 2.

chlorine: Discovered by Scheele in 1774, chlorine is the chemical element 17, of atomic mass Cl = 35,46. It is a greenish yellow gas, with a suffocating odor, dangerous to breathe.

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hydrochloric: Said of acid HCl, a combination of chlorine and hydrogen.

chloride: Combination of chlorine with a simple corp or a radical.


Decanting or decanting: Separation, by difference in gravity, of immiscible products, such as water and an oil.

decoction: Action boil the plants in a liquid.


Enzime: (gr. in, in, and zumê, leaven). Catalyst of protein nature, thermolabile, capable of acting outside the cell or the medium which produces it.

ester: A carboxylic acid R-CO2H reacts with an alcohol R'OH to form the ester R-CO2H and water; this reaction, called “esterification”, is reversible. Thus, in the preparation of the ester, the acid is often replaced by its chloride or its anhydride.

The best known esters are ethyl acetate, solvent, synthetic agent and antispasmodic, and amyl acetate, solvent for cellulose varnishes. Many are contained in natural or artificial fragrances. Finally, the fatty substances are the triesters of glycerin.

ether: An organic compound resulting from the combination, with elimination of water, of an alcohol with an acid or an alcohol.


fermentation: Transformation undergone by organic matter under the action of enzymes secreted by microorganisms.

fluid: (lat. Fluidus; de fluere, flow) Refers to bodies without their own form, which take the form of the vessels which contain them and can flow.

The general term fluid refers to liquids and gas, which have common properties.

Fluor: Simple body, the first member of the halogen family. Fluorine is the chemical element with atomic number 9 and atomic mass F = 19. It was isolated by Moissan in 1886. It is a pale yellow gas, with an irritating odor, difficult to liquefy. It is the most electronegative of all chemical elements and unites with almost all other simple bodies, with a great release of heat.

formate: Salt or ester of formic acid.

formic: (lat. formica, ant) ​​Said of the acid HCO2H and the corresponding aldehyde

fraction: petroleum product obtained by fractionation. (Syn. Cup.)


agar: consistency gelatinous substance, extracted from different seaweed.

glucose: (Gr. Glukus soft) Sugar starch CH2OH- formula (CHOH) 4-CHO.

glyceride: Generic Name esters of glycerine.

Glycerin or glycerol: Trialcool of formula CH2OH-CHOH-CH2OH. It exists as a fatty acid ester in fats and oils. Industry separates it as a by-product of hydrolysis of fat. It is miscible with water.

Biochemistry definitions from H to Z

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