TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

An enzyme that helps to open up the DNA [deoxyribonucleic acid] helix during DNA replication by breaking the hydrogen bonds.  1, record 1, English, - helicase

Record 1,  Textual support,  French

Record 1,  Textual support,  Spanish

Record number: 1, Textual support number: 1 DEF

Cada una de las enzimas que catalizan la ruptura de los puentes de hidrógeno que unen las bases nitrogenadas de las dos cadenas antiparalelas del ácido nucleico, a la vez que se produce la hidrólisis de ATP o GTP.  1, record 1, Spanish, - helicasa

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 CONT

The hydrophilic effect. As the name suggests, a hydrophilic molecule(or an object) likes water molecules and interacts with them strongly and directly. The interactions are mainly electrostatic in nature as the hydrophilic objects are polar/charged and water molecules can easily form HBs [hydrogen bonds] with such species.  2, record 2, English, - hydrophilic%20effect

Record 2,  Textual support,  French

Record 2,  Textual support,  Spanish

Record 3,  Textual support,  English

Record number: 3, Textual support number: 1 CONT

Lipid peroxidation is an endogenous chain reaction that consists in the oxidative degradation of lipids; free radicals or non-radical species attack lipids containing carbon-carbon double bonds, with the hydrogen abstraction from a carbon and oxygen insertion that results in lipid peroxyl radicals and hydroperoxides.  3, record 3, English, - lipid%20peroxidation

Record 3,  Textual support,  French

Record number: 3, Textual support number: 1 CONT

Citons également une autre cible majeure de l'attaque radicalaire : les acides gras polyinsaturés, comme l'acide linoléique et l'acide arachidonique, présents notamment dans les membranes plasmiques. Leur oxydation par les ERO [espèces réactives de l'oxygène], appelée peroxydation lipidique, conduit à la formation de très nombreux produits primaires (les hydroperoxydes) et secondaires (les aldéhydes) dont les activités biologiques sont multiples [...­]  4, record 3, French, - peroxydation%20lipidique

Record 3,  Textual support,  Spanish

Record 4,  Textual support,  English

Record number: 4, Textual support number: 1 DEF

[The process of] modifying the molecular structure of a protein.  1, record 4, English, - denaturation

Record number: 4, Textual support number: 1 OBS

Denaturation involves the breaking of many of the weak linkages, or bonds(e. g. hydrogen bonds), within a protein molecule that are responsible for the highly ordered structure of the protein in its natural(native) state. Denatured proteins have a looser, more random structure; most are insoluble.  1, record 4, English, - denaturation

Record 4,  Textual support,  French

Record number: 4, Textual support number: 1 CONT

En biochimie, la dénaturation est une altération de la structure moléculaire d'une protéine qui rend celle-ci non fonctionnelle. Elle est un changement structurel des protéines ou des acides nucléiques où ils perdent leur structure native et, de cette manière, leur fonctionnement optimal et modifient parfois leurs propriétés physico-chimiques.  1, record 4, French, - d%C3%A9naturation

Record 4,  Textual support,  Spanish

Record 5,  Textual support,  English

Record number: 5, Textual support number: 1 OBS

Ubiquinone is a ring-shaped molecule with two oxygen atoms attached to it(...) In the fully oxidized, or quinone form, both oxygen atoms are connected to the ring by double bonds. Attaching a hydrogen atom to one of the oxygen creates the semiquinone form(...).  1, record 5, English, - semiquinone%20form

Record 5,  Textual support,  French

Record number: 5, Textual support number: 1 OBS

L'ubiquinone est une molécule cyclique sur laquelle sont fixés deux atomes d'oxygène (...) Dans la forme la plus oxydée, ou forme quinonique, les deux atomes d'oxygène sont reliés au cycle benzénique par des doubles liaisons. Dans la forme semiquinonique (...), un atome d'hydrogène est fixé à l'un des oxygènes.  1, record 5, French, - forme%20semiquinonique

Record 5,  Textual support,  Spanish

Record 6,  Textual support,  English

Record number: 6, Textual support number: 1 OBS

Ubiquinone is a ring-shaped molecule with two oxygen atoms attached to it(...). In the fully oxidized, or quinone form, both oxygen atoms are connected to the ring by double bonds. Attaching a hydrogen atom to one of the oxygen creates the semiquinone form, or QH.. In the fully reduced form, called hydroquinone or QH2, both oxygen have hydrogen atoms attached.  1, record 6, English, - hydroquinone%20form

Record 6,  Textual support,  French

Record number: 6, Textual support number: 1 OBS

L'ubiquinone est une molécule cyclique sur laquelle sont fixés deux atomes d'oxygène (...) Dans la forme la plus oxydée, ou forme quinonique, les deux atomes d'oxygène sont reliés au cycle benzénique par des doubles liaisons. Dans la forme semiquinonique ou QH., un atome d'hydrogène est fixé à l'un des oxygènes. A l'état le plus réduit, appelé forme hydroquinonique ou QH2, deux atomes d'hydrogène sont liés aux deux atomes d'oxygène.  1, record 6, French, - forme%20hydroquinonique

Record 6,  Textual support,  Spanish

Record 7,  Textual support,  English

Record number: 7, Textual support number: 1 DEF

The art and science of arranging conditions so that the parts themselves spontaneously assemble into the desired structure.  3, record 7, English, - self%2Dassembly

Record number: 7, Textual support number: 1 CONT

A basic principle in self assembly is selective stickiness: if two molecular parts have complementary shapes and charge patterns, one part has a hollow where the other part has a bump, and one part has a positive charge where the other part has a negative charge, then they will tend to stick together in one particular way. By shaking these parts around, something which thermal noise does for us quite naturally if the parts are floating in solution, the parts will eventually, purely by chance, be brought together in just the right way and combine into a bigger part. This bigger part can combine in the same way with other parts, letting us gradually build a complex whole from molecular pieces by stirring them together and shaking.  3, record 7, English, - self%2Dassembly

Record number: 7, Textual support number: 2 CONT

The key to building electronic devices out of individual molecules is self assembly.  4, record 7, English, - self%2Dassembly

Record number: 7, Textual support number: 1 OBS

Historically, the idea of supramolecular interactions dates back to the famous metaphor of Emil Fischer(1894), who described a selective interaction of molecules as the lock and key principle. Today, supramolecular chemistry has by far surpassed its original focus. Molecular self-assemblies combine several features of covalent and non-covalent synthesis to make large and structurally well-defined assemblies of atoms. Single van der Waals interactions and hydrogen bonds are weak relative to typical covalent bonds and comparable to thermal energies. Therefore, many of these weak non-covalent interactions are necessary in order to achieve molecular stability in self-assembled aggregates. In biology, there are many complex systems of nanoscale structures such as proteins and viruses which are formed by self-assembly. Living systems sum up many weak interactions between chemical entities to make large ones.  1, record 7, English, - self%2Dassembly

Record 7,  Textual support,  French

Record number: 7, Textual support number: 1 DEF

Opération par laquelle des molécules s'associent spontanément pour donner une structure complexe de géométrie bien définie.  2, record 7, French, - autoassemblage

Record number: 7, Textual support number: 1 CONT

L'autoassemblage [offre] la possibilité de construire une molécule complexe et hautement structurée en une seule opération au cours de laquelle plusieurs liaisons [...] sont simultanément formées.  3, record 7, French, - autoassemblage

Record number: 7, Textual support number: 2 CONT

L'autre avantage de l'autoassemblage est de permettre la mise en place provisoire de deux fragments moléculaires en vue d'une réaction ultérieure que l'on souhaite effectuer dans une disposition bien déterminée.  3, record 7, French, - autoassemblage

Record number: 7, Textual support number: 1 PHR

Autoassemblage sur surface.  4, record 7, French, - autoassemblage

Record 7,  Textual support,  Spanish

Record number: 7, Textual support number: 1 CONT

En el autoensamblaje, el nanoconstructor introduce átomos particulares o moléculas dentro de una superficie o dentro de una naoestructura preconstruida. Entonces, las moléculas se alinean (ellas mismas) dentro de posiciones particulares, algunas veces formando uniones débiles y otras veces formando uniones covalentes fuertes, en orden de minimizar la energía total.  1, record 7, Spanish, - autoensamblaje

Record number: 7, Textual support number: 2 CONT

Se comienza con una estructura nanométrica como una molécula y mediante un proceso de montaje o autoensamblado, totalmente automático, se crea un mecanismo mayor que el mecanismo con el que comenzamos.  2, record 7, Spanish, - autoensamblaje

Record 8,  Textual support,  English

Record number: 8, Textual support number: 1 CONT

Because of specific base pairing, if the sequence of one chain(for example, TCGCAT) is known, that of its partner(AGCGTA) is also known. The opposing sequences are referred to as complementary, and the corresponding polynucleotide partners as complementary chains. Despite the relative weakness of the hydrogen bonds holding the base pairs together, each DNA molecule contains so many base pairs that the complementary chains never spontaneously separate under physiological conditions.  1, record 8, English, - complementary%20chain

Record 8,  Textual support,  French

Record number: 8, Textual support number: 1 CONT

La molécule ADN est composée de deux chaînes polynucléotidiques complémentaires liées par des liaisons hydrogènes, ce qui implique l'existence de ponts hydrogènes spécifiques. Lors de la réplication chaque chaîne a un rôle matriciel, ce qui implique un mode de réplication semi-conservatif. L'hypothèse de Watson et Crick suggère que la polarité des chaînes complémentaires de l'ADN est inversée et elle suppose en sus que séparation et déspiralisation des chaînes débutent d'un côté de la molécule et se poursuivent progressivement d'un bout à l'autre de la chaîne à la manière de l'ouverture d'une fermeture éclair, la synthèse au sens physique du terme se faisant donc dans une seule direction, ce qui implique que cette synthèse se fait dans des directions chimiques opposées.  2, record 8, French, - cha%C3%AEne%20compl%C3%A9mentaire

Record 8,  Textual support,  Spanish

Record 9,  Textual support,  English

Record number: 9, Textual support number: 1 DEF

The temperature at which 50% of the total hyperchromicity of double-stranded DNA is achieved.  2, record 9, English, - melting%20temperature

Record number: 9, Textual support number: 1 OBS

It increases in a linear fashion with the content of G-C base pairs, which have three hydrogen bonds and are thus more stable than A-T pairs.  2, record 9, English, - melting%20temperature

Record number: 9, Textual support number: 2 OBS

Tm: T_m.  3, record 9, English, - melting%20temperature

Record 9,  Textual support,  French

Record number: 9, Textual support number: 1 DEF

Température moyenne à laquelle 50 % de l'ADN double brin est dissocié. [Définition normalisée par l'AFNOR et reproduite avec son autorisation.]  3, record 9, French, - temp%C3%A9rature%20de%20fusion

Record number: 9, Textual support number: 1 OBS

Cette température dépend du pourcentage de GC (guarine, cytosine) et de la composition du milieu. [Observation reproduite avec l'autorisation de l'AFNOR.]  3, record 9, French, - temp%C3%A9rature%20de%20fusion

Record number: 9, Textual support number: 2 OBS

Tm : T_m.  4, record 9, French, - temp%C3%A9rature%20de%20fusion

Record number: 9, Textual support number: 3 OBS

température de fusion : terme normalisé par l'AFNOR et publié au Journal officiel de la République française le 22 septembre 2000.  5, record 9, French, - temp%C3%A9rature%20de%20fusion

Record 9,  Textual support,  Spanish

Record 10,  Textual support,  English

Record number: 10, Textual support number: 1 CONT

Proteins are organized as a hierarchy of structures. The sequence is organized by variation of the main-chain torsion angles and the formation of hydrogen bonds into secondary structures such as [alpha]-helices [alpha], [beta]-strands [beta] and turns. Particular combinations of these secondary structural elements such as [alpha][alpha], [beta][alpha][beta] or [beta][beta] known as motifs are frequently found in the structures of globular proteins and appear to have a limited number of three-dimensional arrangements.  1, record 10, English, - motif

Record 10,  Textual support,  French

Record number: 10, Textual support number: 1 DEF

Séquence conservée de nucléotides ou d’acides aminés qui peut être associée à certaines fonctions, respectivement, d’un segment d’ADN ou d’une protéine.  1, record 10, French, - motif

Record 10,  Textual support,  Spanish

Record number: 10, Textual support number: 1 DEF

Secuencia conservada de nucleótidos o aminoácidos que puede asociarse con alguna función de un fragmento de ADN o de una proteína, respectivamente.  1, record 10, Spanish, - motivo

Record 11,  Textual support,  English

Record number: 11, Textual support number: 1 CONT

ß-Sheets are formed when two or more almost fully extended polypeptide chains are brought together side by side, so that regular hydrogen bonds can form between the peptide backbone amide NH and carbonyl oxygen groups of adjacent chains.... All the peptide linkages participate in this cross-linking and thus lend the structure great stability; the R groups lie above or below the zigzagging planes of the pleated sheet.... The structure of the ß-sheet makes up extensive regions of the core of most(though not all) globular proteins.  3, record 11, English, - beta%2Dsheet

Record 11,  Textual support,  French

Record number: 11, Textual support number: 1 CONT

L. Pauling avait à peine découvert [...] les hélices alpha [...] qu'il observa une seconde configuration stable : les feuillets bêta. Dans ce type de structure, des segments rectilignes de la chaîne polypeptidique sont juxtaposés en zigzag, comme un mètre d'architecte incomplètement replié; des liaisons hydrogène relient les segments adjacents, appelés brins bêta. Dans cette structure comme dans les hélices alpha, des liaisons s'établissent entre les groupes NH et les groupes CO de la chaîne polypeptidique principale. [...] Toutes les liaisons peptidiques participent à ces liaisons, ce qui assure à cette structure une grande stabilité.  2, record 11, French, - feuillet%20b%C3%AAta

Record number: 11, Textual support number: 1 OBS

Le feuillet bêta est aussi appelé «feuillet plissé» ou «conformation plissée».  2, record 11, French, - feuillet%20b%C3%AAta

Record 11,  Textual support,  Spanish

Record 12,  Textual support,  English

Record number: 12, Textual support number: 1 DEF

[A] linear array of amino acids that are linked together by peptide bonds in a protein.  2, record 12, English, - polypeptide%20chain

Record number: 12, Textual support number: 1 CONT

Hydrogen bonds... play a major part in holding together different regions of polypeptide chain in a folded protein molecule, and they are crucially important for many of the binding interactions observed on protein surfaces. Once they are outside the cytoplasm, secreted or cell-surface proteins often form additional covalent intrachain bonds. For example, the formation of disulfide bonds(also called S-S bridges) between neighboring cysteine-SH groups in a folded polypeptide chain frequently serves to stabilize the three-dimensional structure of extracellular proteins, although they are not required for the specific folding of the molecule.  3, record 12, English, - polypeptide%20chain

Record 12,  Textual support,  French

Record number: 12, Textual support number: 1 DEF

Polymère non ramifié de résidus successifs d'aminoacides liés par covalence (liaisons peptidiques), résultant de l'information monodimensionnelle contenue dans l'ADN et constituant le squelette des protéines.  2, record 12, French, - cha%C3%AEne%20polypeptidique

Record number: 12, Textual support number: 1 CONT

Dans une longue chaîne polypeptidique, les liaisons, qui autorisent une libre rotation des atomes qu'elles relient, sont nombreuses et donnent au squelette protéique une grande flexibilité. Chaque molécule de protéine peut donc, en principe, adopter un très grand nombre de formes différentes, ou conformations. Toutefois, dans des conditions biologiques, la plupart des chaînes polypeptidiques ne se replient que selon une seule de ces conformations. Ceci est dû au fait que les chaînes aminés latérales des différents acides aminés s'associent entre elles et avec l'eau pour former une variété de liaisons faibles non covalentes.  3, record 12, French, - cha%C3%AEne%20polypeptidique

Record 12,  Textual support,  Spanish

Record 13,  Textual support,  English

Record number: 13, Textual support number: 1 CONT

The "bonding number" of a neutral heteroatom in the corresponding unsubstituted parent compound is defined as the sum of the total number of bonds to adjacent skeletal atoms, if any, and the number of hydrogen atoms attached to it, if any.  2, record 13, English, - bonding%20number

Record 13,  Textual support,  French

Record number: 13, Textual support number: 1 DEF

Nombre total de liaisons à deux électrons qu'un atome d'un hydrure fondamental peut contracter avec les atomes adjacents, y compris ceux d'hydrogène.  2, record 13, French, - indice%20de%20valence%20formelle

Record number: 13, Textual support number: 1 OBS

indice de valence formelle : terme et définition publiés au Journal officiel de la République française le 8 octobre 2003.  3, record 13, French, - indice%20de%20valence%20formelle

Record 13,  Textual support,  Spanish

Record 14,  Textual support,  English

Record number: 14, Textual support number: 1 DEF

A process based on the fact that isolated RNA on being mixed with denatured(single-stranded) DNA under appropriate conditions forms hydrogen bonds with the complementary DNA sequences leading to DNA-RNA hybrids.  1, record 14, English, - DNA%2DRNA%20hybridization

Record number: 14, Textual support number: 1 OBS

The rate of hybridization is limited by the collision frequency of complementary nucleotide sequences. It is a useful tool for localizing genes in chromosomes.  1, record 14, English, - DNA%2DRNA%20hybridization

Record 14,  Textual support,  French

Record number: 14, Textual support number: 1 DEF

Formation in vitro d'hybrides ADN-ARN par appariement des séquences nucléotidiques complémentaires appartenant à un même brin ou deux brins différents.  2, record 14, French, - hybridation%20ADN%2DARN

Record 14,  Textual support,  Spanish

Record number: 14, Textual support number: 1 CONT

Las técnicas de desnaturalización y posterior renaturalización se utilizan para conseguir la hibridación de ácidos nucleicos, es decir, una vez separadas las dos hebras del ADN doble hélice, es posible volver a formar una doble hélice con una hebra de ADN que sea complementaria (hibridación de ADN con ADN) o volver a formar una doble hélice con un segmento de ARN que contenga la secuencia complementaria (hibridación de ADN con ARN).  1, record 14, Spanish, - hibridaci%C3%B3n%20de%20ADN%20con%20ARN

Record 15,  Textual support,  English

Record number: 15, Textual support number: 1 DEF

The pairing of nitrogenous bases in the polynucleotide chains by hydrogen bonds in a specific manner  1, record 15, English, - base%20pairing

Record 15,  Textual support,  French

Record number: 15, Textual support number: 1 DEF

Association par liaisons hydrogènes de deux bases dites complémentaires d'un acide nucléique, soit une base purique et une base pyrimidique.  2, record 15, French, - appariement%20des%20bases

Record 15,  Textual support,  Spanish

Record 16,  Textual support,  English

Record number: 16, Textual support number: 1 DEF

Enzyme composed of identical subunits or unlike subunits.  2, record 16, English, - oligomeric%20enzyme

Record number: 16, Textual support number: 1 CONT

Oligomeric enzymes are usually dissociated into subunits by treatment with denaturing agents such as guanidine hydrochloride. The forces involved in the association of the subunits are thus of the weak, non-covalent type which are involved in stabilizing the folded structure of a polypeptide chain i. e. hydrogen bonds, electrostatic forces, van der Waals forces, and hydrophobic forces.  3, record 16, English, - oligomeric%20enzyme

Record number: 16, Textual support number: 1 OBS

Many investigators in the late sixties questioned the very existence of uneven numbered oligomers. However, by now we know of well-defined cases for trimeric enzymes.... Pentameric enzymes are rare, whereas no heptamer has so far been found. It is therefore justifiable to say that even-numbered oligomers are much more common than those having an uneven number of protomers, but the latter also exist.... Very few true oligomeric enzymes contain ten, twelve or more subunits.  1, record 16, English, - oligomeric%20enzyme

Record 16,  Textual support,  French

Record number: 16, Textual support number: 1 DEF

Enzyme [...] formé de plusieurs chaînes (ou sous-unités) identiques ou différentes. Lorsque les enzymes comprennent des sous-unités identiques, chacune des chaînes est bien entendu porteuse d'un centre actif : un enzyme tétramérique a 4 centres actifs. Dans cette catégorie d'enzymes [...] on trouve les enzymes allostériques (qui représentent 10-20 % des enzymes à structure quaternaire).  1, record 16, French, - enzyme%20oligom%C3%A8re

Record number: 16, Textual support number: 1 CONT

Dans le modèle de Monod, Wyman et Changeux, l'enzyme oligomère peut prendre deux états conformationnels différents : R et T dans lesquels, toutes les sous-unités changent leur conformation d'une façon concertée. Les deux états sont en équilibre. En l'absence de substrat, la plus grande partie des molécules de l'enzyme prennent l'état T. Puisque le substrat se lie de préférence à l'état R, l'addition du substrat déplace l'équilibre vers cet état R. De cette façon, la liaison des premières molécules du substrat favorise la liaison de celles qui suivent, étant donné que plus de molécules enzymatiques prennent l'état R.  2, record 16, French, - enzyme%20oligom%C3%A8re

Record 16,  Textual support,  Spanish

Record 17,  Textual support,  English

Record number: 17, Textual support number: 1 DEF

An attraction or repulsion between molecules.  2, record 17, English, - intermolecular%20force

Record number: 17, Textual support number: 1 OBS

Intermolecular forces are much weaker than chemical bonds. Hydrogen bonds, dipole-dipole interactions, and London forces are examples of intermolecular forces.  2, record 17, English, - intermolecular%20force

Record 17,  Textual support,  French

Record number: 17, Textual support number: 1 CONT

La force intermoléculaire qui s'exerce entre molécules non polaires s'appelle : (a) Liaison hydrogène (b) Force de London (c) Force de Coulomb.  1, record 17, French, - force%20intermol%C3%A9culaire

Record 17,  Textual support,  Spanish

Record number: 17, Textual support number: 1 DEF

Fuerza de atracción o repulsión entre moléculas polares.  2, record 17, Spanish, - fuerza%20intermolecular

Record number: 17, Textual support number: 1 CONT

Las fuerzas intermoleculares son fuerzas electromagnéticas las cuales actúan entre moléculas o entre regiones ampliamente distantes de una macromolécula. En orden decreciente de fuerza, las fuerzas intermoleculares son: Interacciones iónicas, Puente de hidrógeno, Interacciones dipolo-dipolo, Fuerza de London.  3, record 17, Spanish, - fuerza%20intermolecular

Record 18,  Textual support,  English

Record number: 18, Textual support number: 1 CONT

One method used to assess the effect of ions on protein conformation is to measure the melting temperature (T_m) which is the midpoint of the reversible folding ... unfolding transformation or order = disorder transformation. It can be illustrated by the thermally induced conversion of collagen from the triple helical order form to the disordered random coil conformation where T_m is the temperature at which the helical and the coil forms are equally stable. T_m decreases by about 16[degrees c] per mole if calcium chloride is added and is approximately linear with molarity. The transformation can be followed by a plot of change in optical rotation against temperature.  3, record 18, English, - melting%20temperature

Record number: 18, Textual support number: 1 OBS

Ions can potentially affect the three major factors namely hydrogen bonding, hydrophobic bonds and electrostatic interaction, that hold an enzyme in an optimal conformation.  3, record 18, English, - melting%20temperature

Record number: 18, Textual support number: 2 OBS

The term Tm should read T[subscript]m.  4, record 18, English, - melting%20temperature

Record number: 18, Textual support number: 3 OBS

Because of technical constraints, the formula(s) given in CBT-167 could not be reproduced.  4, record 18, English, - melting%20temperature

Record 18,  Textual support,  French

Record number: 18, Textual support number: 1 DEF

Température à laquelle la moitié des molécules ont subi une transformation réversible de type déploiement de chaîne ou dénaturation.  2, record 18, French, - temp%C3%A9rature%20de%20fusion

Record number: 18, Textual support number: 1 OBS

Ce terme est aussi employé pour désigner le point médian de la variation de température nécessaire pour séparer les deux brins d'une molécule d'ADN  2, record 18, French, - temp%C3%A9rature%20de%20fusion

Record 18,  Textual support,  Spanish

Record 19,  Textual support,  English

Record number: 19, Textual support number: 1 DEF

Broad class of proteins constituted of one or more polypeptide chains or groups of such chains; they are elongated, very asymmetric molecules whose length may be 10 or more times their diameter. The polypeptide chains may be coiled and may be cross-linked by disulfide bonds and by hydrogen bonds.  2, record 19, English, - fibrous%20protein

Record number: 19, Textual support number: 1 CONT

Proteins can be placed in two major classes, fibrous and globular.... Fibrous proteins are physically tough and are insoluble in water or dilute salt solutions. They are the basic structural elements in the connective tissue of higher animals. Examples are collagen of tendons and bone matrix, [alpha]-keratin of hair, horn, skin, nails, and feathers, and elastin of elastic connective tissue.  3, record 19, English, - fibrous%20protein

Record number: 19, Textual support number: 1 OBS

The principal difference between the compact globular proteins ... and ... fibrous structural proteins is that the latter are generally built from repeating motifs which enable them to grow into large structural assemblies. Silk fibroin is just such a large assembly, but with a different motif from collagen and [alpha]-keratin.  4, record 19, English, - fibrous%20protein

Record 19,  Textual support,  French

Record number: 19, Textual support number: 1 DEF

Protéines physiquement résistantes qui constituent un matériel insoluble dans l'eau et les solutions salines diluées. Elles sont constituées de chaînes polypeptidiques rangées parallèlement le long d'un même axe pour former de longues fibres. Ces protéines forment les structures élémentaires du tissu conjonctif des animaux supérieurs.  2, record 19, French, - prot%C3%A9ine%20fibreuse

Record number: 19, Textual support number: 1 CONT

Chez les vertébrés une protéine fibreuse, le collagène est la protéine extracellulaire de structure la plus importante du tissu conjonctif et de l'os. Les fibrilles de collagène contribuent aussi à la formation de structures continues qui unissent les cellules pour former un tissu. Deux autres protéines fibreuses existent chez les vertébrés, l'élastine du tissu élastique et la kératine [alpha].  3, record 19, French, - prot%C3%A9ine%20fibreuse

Record 19,  Textual support,  Spanish

Record 20,  Textual support,  English

Record number: 20, Textual support number: 1 DEF

To subject to hydrolysis.  3, record 20, English, - hydrolyze

Record number: 20, Textual support number: 1 CONT

Enzymes sometimes form transient covalent bonds with their substrates. In one example, a carboxyl group in a polypeptide chain forms a covalent bond at an activated serine residue of a protease as the backbone chain is broken. When the unbound portion of the polypeptide chain has diffused away, a second step occurs in which a water molecule hydrolyzes the newly formed covalent bond, thereby releasing the portion of the polypeptide bound to the enzyme surface and restoring a hydrogen atom to the serine.  4, record 20, English, - hydrolyze

Record number: 20, Textual support number: 1 OBS

See "hydrolysis".  5, record 20, English, - hydrolyze

Record 20,  Textual support,  French

Record number: 20, Textual support number: 1 DEF

Soumettre à l'hydrolyse.  2, record 20, French, - hydrolyser

Record number: 20, Textual support number: 1 CONT

Des développements liés à la mise en évidence récente d'enzymes capables d'hydrolyser spécifiquement certains composés organophosphorés [...] peuvent actuellement être envisagés. Ces enzymes devraient permettre d'une part de doser spécifiquement l'un ou l'autre des composés organophosphorés présents dans un échantillon, et d'autre part de détoxifier un milieu contaminé par l'un de ces composés.  3, record 20, French, - hydrolyser

Record 20,  Textual support,  Spanish

Record 21,  Textual support,  English

Record number: 21, Textual support number: 1 DEF

The yellow crumb is dissolved in aqueous caustic solution. The large xanthate substituents on the cellulose force the chains apart, reducing the interchain hydrogen bonds and allowing water molecules to solvate and separate the chains, leading to solution of the otherwise insoluble cellulose...  2, record 21, English, - dissolving

Record 21,  Textual support,  French

Record number: 21, Textual support number: 1 CONT

Certaines fibres artificielles sont obtenues par dissolution de la cellulose dans une liqueur cuproammoniacale.  2, record 21, French, - dissolution

Record 21,  Textual support,  Spanish

Record 22,  Textual support,  English

Record number: 22, Textual support number: 1 CONT

In reference to monohydric alcohols, amines, and a few related compounds, this term [primary], together with secondary and tertiary, describes the molecular structure of isomeric or chemically similar individuals. Monohydric alcohols are based on the methanol group,-C-OH, in which three of the bonds [up, down and left side] of the methanol carbon may be attached either to hydrogen atoms or to alkyl groups.... A secondary alcohol has two alkyl groups and one hydrogen.... The three types can be readily identified by the number of hydrogen atoms attached to the central(methanol) carbon atom : if it is 2 or more, the alcohol is primary; if 1, it is secondary; and if zero, it is tertiary. For example, CH₃CH₂OH; is primary;(CH₃) CHOH; is secondary;(CH₃) ₃COH is tertiary.  1, record 22, English, - secondary%20alcohol

Record 22,  Textual support,  French

Record number: 22, Textual support number: 1 DEF

Nom générique des alcools renfermant le groupement bivalent -CHOH-.  2, record 22, French, - alcool%20secondaire

Record number: 22, Textual support number: 1 CONT

On distingue trois classes d'alcools, selon le nombre d'atomes d'hydrogènes attachés à l'atome de carbone porteur du groupe OH : les alcools tertiaires R₃COH, les alcools secondaires R₂CHOH et les alcools primaires RCH₂OH (auxquels se rattache le méthanol CH₃OH).  3, record 22, French, - alcool%20secondaire

Record 22,  Textual support,  Spanish

Record 23,  Textual support,  English

Record number: 23, Textual support number: 1 DEF

Hydrogen bonds formed between atoms within the same molecule.  1, record 23, English, - intramolecular%20hydrogen%20bonding

Record 23,  Textual support,  French

Record number: 23, Textual support number: 1 DEF

Pont hydrogène (...) entre deux parties de la même molécule. On dit alors qu'il y a "chélation", appellation dérivée de l'image d'une pince de crabe (...), l'hydrogène étant serré entre deux autres atomes électronégatifs comme l'oxygène, par exemple.  1, record 23, French, - pont%20hydrog%C3%A8ne%20intra%2Dmol%C3%A9culaire

Record 23,  Textual support,  Spanish

Record 24,  Textual support,  English

Record number: 24, Textual support number: 1 CONT

Near infrared reflectance spectroscopy(NIRS) is an accurate, precise, and rapid alternative to wet chemistry procedures for determining concentrations of major classes of chemical compounds in organic materials, such as plant foliage. The method utilizes reflectance signals resulting from bending and stretching vibrations in molecular bonds between carbon, nitrogen, hydrogen, and oxygen. Calibration is required to correlate the spectral response of each sample at individual wavelengths to known chemical concentrations from laboratory analyses.  4, record 24, English, - near%20infrared%20reflectance%20spectroscopy

Record 24,  Textual support,  French

Record number: 24, Textual support number: 1 CONT

Spectrométrie dans le proche infrarouge (NIRS). C'est actuellement la plus performante des méthodes de prédiction pour mesurer la digestibilité de la matière organique qui permet d'apprécier la valeur énergétique d'un fourrage. Lorsqu'on soumet un ensemble de molécules à un rayonnement lumineux infrarouge (longueurs d'ondes comprises entre 780 et 2500 nm), une partie du rayonnement est absorbée, une autre réfléchie. Les longueurs d'ondes absorbées sont spécifiques à chaque constituant et le degré d'absorption proportionnel à sa concentration. Le spectromètre indique ainsi le spectre réfléchi et permet d'en déduire le spectre d'absorption. C'est une méthode de mesure indirecte. Le spectre d'absorption permet de caractériser un produit exactement comme une empreinte digitale permet d'identifier un criminel par comparaison de «l'empreinte» observée avec une banque de données.  3, record 24, French, - spectroscopie%20de%20r%C3%A9flectance%20dans%20le%20proche%20infrarouge

Record 24,  Textual support,  Spanish

Record 25,  Textual support,  English

Record number: 25, Textual support number: 1 DEF

Of a chemical compound, the state in which not all the available valence bonds along the alkyl chain are satisfied; in such compounds the extra bonds usually form double or triple bonds(chiefly with carbon). Thus unsaturated compounds are more reactive than saturated compounds, as other elements readily add to the unsaturated linkage. An unsaturated compound... has fewer hydrogen atoms or equivalent groups than the corresponding saturated compound....  1, record 25, English, - unsaturation

Record 25,  Textual support,  French

Record number: 25, Textual support number: 1 DEF

Caractère des composés organiques non saturés et, par extension, des fonctions organiques, telles que liaisons multiples, ou particularité structurale, telle que cycle, qui font qu'une molécule ne contient pas le nombre maximal d'atomes d'hydrogène compatibles avec le nombre des atomes présents de carbone, azote, oxygène, etc.  1, record 25, French, - insaturation

Record 25,  Textual support,  Spanish

Record 26,  Textual support,  English

Record number: 26, Textual support number: 1 CONT

The base-pairing rule is significant because : I. It explains Chargaff's rules. II. It suggests the general mechanisms for DNA replication. If bases form specific pairs, the information on one strand complements that along the other. III. It dictates the combination of complementary base pairs, but places no restriction on the linear sequence of nucleotides along the length of a DNA strand. The sequence of bases can be highly variable which makes it suitable for coding genetic information. IV. Though hydrogen bonds between paired bases are weak bonds, collectively they stabilize the DNA molecule. Van der Waals forces and hydrophobic interactions between stacked bases also help stabilize DNA.  2, record 26, English, - base%2Dpairing%20rules

Record 26,  Textual support,  French

Record number: 26, Textual support number: 1 DEF

Règle universelle d'appariement des bases des acides nucléiques, selon laquelle A s'associe avec T (ou U) et G avec C.  2, record 26, French, - compl%C3%A9mentarit%C3%A9

Record 26,  Textual support,  Spanish

Record 27,  Textual support,  English

Record number: 27, Textual support number: 1 DEF

A highly coloured, alkali-soluble and partially water soluble chlorinated phenolic material formed from the reaction of chlorine and the ligneous component of chemical pulp.  2, record 27, English, - chlorolignin

Record number: 27, Textual support number: 1 OBS

Chlorine reacts with lignin by a) Addition of chlorine to double bonds; b) Substitution of chlorine for hydrogen atoms in benzene rings; c) Oxidation.  2, record 27, English, - chlorolignin

Record 27,  Textual support,  French

Record number: 27, Textual support number: 1 DEF

Substance phénolique chlorée, très colorée, soluble dans l'alcali et partiellement soluble dans l'eau, qui se forme à partir de la réaction du chlore avec les composants ligneux de la pâte chimique.  2, record 27, French, - chlorolignine

Record number: 27, Textual support number: 1 OBS

Le chlore réagit à la lignine par a) l'addition de chlore à des doubles liaisons; b) la substitution d'atomes d'hydrogène par le chlore dans les cycles aromatiques; c) l'oxydation.  2, record 27, French, - chlorolignine

Record number: 27, Textual support number: 2 OBS

On trouvera le terme «chlorolignine» sous l'article 3.6.2.1. du «Cours de formation papetière» de Jean Vilars (code : VIPAP).  3, record 27, French, - chlorolignine

Record 27,  Textual support,  Spanish

Record 28,  Textual support,  English

Record number: 28, Textual support number: 1 OBS

Heating DNA molecules to temperatures just below 100 [degrees] C breaks the hydrogen bonds holding the complementary strands together; they then quickly separate from each other(DNA denaturation). If the temperature is gradually lowered, the complementary strands again form the correct hydrogen bonds and the double-helical form is regained(renaturation of DNA). If, however, this gentle cooling is done in the presence of single-stranded RNA that has been synthesized on homologous DNA, then DNA-RNA hybrids form as well as denatured DNA double helices. These DNA-RNA hybrids are very specific and form only if some of the nucleotide sequences in the DNA are complementary to the RNA nucleotide sequences.  1, record 28, English, - renatured%20DNA

Record 28,  Textual support,  French

Record 28,  Textual support,  Spanish

Record 29,  Textual support,  English

Record number: 29, Textual support number: 1 CONT

Halocarbons containing hydrogen atoms or double bonds(unsaturated) in their chemical structure are partially removed in the troposphere, whereas saturated, completely halogenated halocarbons(such as clorofluoromethanes) are very stable and will be transported into the stratosphere virtually intact.  2, record 29, English, - completely%20halogenated%20hydrocarbon

Record number: 29, Textual support number: 1 OBS

The word "halocarbon "by itself" means "halogenated hydrocarbon", the repetition of the adjective "halogenated" is useless for this expression.  3, record 29, English, - completely%20halogenated%20hydrocarbon

Record 29,  Textual support,  French

Record number: 29, Textual support number: 1 DEF

Dérivé d'un hydrocarbure composé de carbone et d'un ou de plusieurs halogènes, ces derniers remplaçant entièrement l'hydrogène.  1, record 29, French, - hydrocarbure%20enti%C3%A8rement%20halog%C3%A9n%C3%A9

Record 29,  Textual support,  Spanish

Record 30,  Textual support,  English

Record number: 30, Textual support number: 1 DEF

A saturated carbon hydrogen compound with all carbon bonds filled; that is there are no double or triple bonds as in olefins and acetylenics.  1, record 30, English, - saturated%20hydrocarbon

Record 30,  Textual support,  French

Record number: 30, Textual support number: 1 DEF

Composé hydrocarboné, qui ne contient que des liaisons simples carbone-carbone et auquel on ne peut ajouter, sans substitution, d'autres éléments ou composés.  1, record 30, French, - hydrocarbure%20satur%C3%A9

Record number: 30, Textual support number: 1 OBS

Les hydrocarbures saturés sont généralement des substances peu actives chimiquement. Les alcanes et les carbures cyclaniques sont des hydrocarbures saturés.  1, record 30, French, - hydrocarbure%20satur%C3%A9

Record 30,  Textual support,  Spanish

Record 31,  Textual support,  English

Record number: 31, Textual support number: 1 DEF

The coiled conformation of a polypeptide which is maintained by hydrogen bonding between the CO and NH groups of the peptide bonds of adjacent coils; in natural polypeptides the helix is right-handed.(Gk helix coil).  1, record 31, English, - alpha%20helix

Record 31,  Textual support,  French

Record number: 31, Textual support number: 1 DEF

Configuration spatiale de nombreuses protéines, caractérisée par une disposition des acides aminés constitutifs selon une hélice dont le pas est de 0,51 à 0.54 nm. Cette disposition hélicoïdale assure une solide cohésion moléculaire grâce à des liaisons hydrogènes entre les spires successives de l'hélice.  1, record 31, French, - h%C3%A9lice%20alpha

Record 31,  Textual support,  Spanish