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reaction US English

An action performed or a feeling experienced in response to a situation or event

reaction US Thesaurus

his reaction had bewildered her

dark reaction US English

The cycle of reactions (the Calvin cycle) that occurs in the second phase of photosynthesis and does not require the presence of light. It involves the fixation of carbon dioxide and its reduction to carbohydrate and the dissociation of water, using chemical energy stored in ATP

reaction coil US English

A coiled tube in which a reaction takes place.

reaction jet US English

A jet engine used to provide intermittent thrust for changing or correcting the velocity of a spacecraft; also in extended use.

reaction rim US English

A zone of one mineral enclosing another and formed by the reaction of the core with its surroundings.

reaction shot US English

(In a film or video recording) a portrayal of a person’s response to an event or to a statement made by another

reaction time US English

The length of time taken for a person or system to respond to a given stimulus or event

reaction type US English

(In behavioural typology) a physical or personality type which is expected to react in specific ways to a stimulus.

reaction wood US English

A type of wood with modified anatomical and biochemical features found in leaning stems and in the lower (in gymnosperms) or upper (in angiosperms) sides of branches.

reaction word US English

(In a word association test) a word given by a subject in response to a stimulus word.

skin reaction US English

An irritation or inflammation of the skin caused by an adverse response to a substance that has been inhaled, ingested, touched, or purposefully applied or injected for a skin test.

alarm reaction US English

The physiological response to stress in many vertebrates, mediated largely by hormones.

aldol reaction US English

= aldol condensation.

chain reaction US English

A chemical reaction or other process in which the products themselves promote or spread the reaction, which under certain conditions may accelerate dramatically

cross-reaction US English

The reaction of an antibody with an antigen other than the one that gave rise to it

lepra reaction US English

Acute exacerbation of leprosy, occurring during certain treatments for the condition, and typically characterized by fever, redness and swelling of skin lesions, and often acute neuritis, occurring especially during leprosy treatment; an instance of this.

light reaction US English

The reaction of something, especially the iris of the eye, to different intensities of light

Millon reaction US English

The characteristic reaction of Millon's reagent with phenolic compounds, in which a white precipitate is produced that becomes pink or reddish on heating (described by Millon for a phenolic protein in Compte Rendu Hebd. de l'Acad. des Sci. (1849) 28 40).

phase reaction US English

A chemical or physical change which involves the transfer of material between phases, or the appearance or disappearance of a phase.

Prins reaction US English

An addition reaction between an alkene and an aldehyde in the presence of an acid catalyst, yielding a 1,3-diol, an allyl alcohol, or a 1,3-dioxan, depending on the particular reactants and conditions used.

pupil reaction US English

The response of the pupil to light, especially as a test of neurological function.

rapid-reaction US English

Chemistry. Of, relating to, or involving a rapid chemical reaction.

reaction centre US English

The site at which physical or chemical reaction occurs; (Biochemistry) the complex of protein and light-harvesting pigments at which the light reactions occur during photosynthesis.

reaction drive US English

A fictitious propulsion system for a spacecraft, powered by or involving some kind of reaction.

reaction engine US English

Any engine in which motive power is derived from the reaction exerted by a jet of escaping fluid (usually a gas).

reaction force US English

A force equal and opposite to a force giving rise to it; compare sense 2b.

reaction index US English

An assessment of an audience's reaction to a programme.

reaction motor US English

= reaction engine.

reaction vessel US English

= reaction chamber.

reaction wheel US English

A waterwheel impelled by the action of escaping water.

redox reaction US English

A reaction in which oxidation of one reactant is coupled with reduction of another.

signal reaction US English

An immediate, non-rational, conditioned response to a stimulus or a symbol.

addition reaction US English

A reaction in which one molecule combines with another to form a larger molecule with no other products

chemical reaction US English

A process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction

nuclear reaction US English

A change in the identity or characteristics of an atomic nucleus that results when it is bombarded with an energetic particle, as in fission, fusion, or radioactive decay

Pasteur reaction US English

= Pasteur effect. Now historical.

Perkin's reaction US English

Any of a number of reactions discovered by Perkin, especially that in which, typically, an arylacrylic acid is formed by the condensation of an aromatic aldehyde with the anhydride of an aliphatic acid, in the presence of the sodium salt of the latter.

plasmal reaction US English

A modification of the Feulgen reaction for detecting plasmalogens and aldehydes in tissue.

reaction chamber US English

A vessel in which a chemical reaction occurs, especially in an industrial process.

reaction formation US English

The tendency of a repressed wish or feeling to be expressed at a conscious level in a contrasting form

reaction machine US English

= reaction engine.

reaction mechanism US English

The sequence of actions which together constitute a reaction; specifically the steps (as bond breakage or formation, electron transfer, etc.) involved in a chemical reaction.

reaction mixture US English

A mixture in which a reaction occurs; a mixture of reactants.

reaction pattern US English

An established pattern of reacting to something; specifically a fixed or unchanging behavioural or neurological reaction.

reaction process US English

A process constituting or involving a reaction, especially a chemical reaction.

reaction turbine US English

A turbine in which the working fluid accelerates or expands and undergoes a drop in pressure in passing across or through the rotor, which is thereby propelled in the opposite direction to the flow.

runaway reaction US English

A disorder found in troubled adolescents who perceive running away to be a solution to difficulties in the home, at school, etc.

carbylamine reaction US English

A reaction in which a carbylamine is formed from an amine, employed in the carbylamine test; the test itself.

precipitin reaction US English

The reaction of antibody and antigen to form a visible precipitate; an instance of this.

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