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Encyclopedia > Ethylene
Ethylene
Ethylene Ethylene
General
Systematic name Ethene
Molecular formula C2H4
SMILES C=C
Molar mass 28.05 g/mol
Appearance colourless gas
CAS number [74-85-1]
Properties
Density and phase 1.178 g/l at 15 °C, gas
Solubility of gas in water 25 mL/100 mL (0 °C)
12 mL/100 mL (25 °C)[1]
Melting point −169.1 °C
Boiling point −103.7 °C
Structure
Molecular shape planar
Dipole moment zero
Symmetry group D2h
Thermodynamic data
Std enthalpy of
formation
ΔfH°gas
+52.47 kJ/mol
Standard molar
entropy
S°gas
219.32 J·K−1·mol−1
Hazards
MSDS External MSDS
EU classification Extremely flammable (F+)
NFPA 704

Image File history File links This is a lossless scalable vector image. ... Image File history File links Download high-resolution version (1100x908, 138 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Ethylene Polyethylene User:Benjah-bmm27/Gallery User:Ben Mills/Gallery ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article does not cite its references or sources. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that this article or section be merged with Solution. ... This article describes water from a scientific and technical perspective. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... four sp³ orbitals three sp² orbitals In chemistry, hybridisation or hybridization (see also spelling differences) is the concept of mixing atomic orbitals to form new hybrid orbitals suitable for the qualitative description of atomic bonding properties. ... The Earths magnetic field, which is approximately a dipole. ... The symmetry group of an object (e. ... The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy that accompanies the formation of 1 mole of a substance in its standard state from its constituent elements in their standard states (the most stable form of the element at 1 atmosphere... In chemistry, the standard molar entropy is the entropy content of one mole of substance, under conditions of standard temperature and pressure. ... An example MSDS in a US format provides guidance for handling a hazardous substance and information on its composition and properties. ... This page provides supplementary chemical data on ethylene. ... Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main source of European Union law concerning chemical safety. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links NFPA_704. ...

4
1
2
 
R-phrases R12, R67
S-phrases (S2), S9, S16,
S33, S46
Flash point Flammable gas
Explosive limits 2.7–36.0%
Autoignition temperature 490 °C
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Other alkenes Propene
Butene
Related compounds Ethane
Acetylene
Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Ethylene (or IUPAC name ethene) is the chemical compound with the formula C2H4. It is the simplest alkene. Because it contains a double bond, ethylene is called an unsaturated hydrocarbon or an olefin. It is exceedingly important in industry and even has a role in biology as a hormone.[2] Ethylene is the organic compound produced on the largest scale: global production of ethylene exceeded 75 million metric tonnes per year in 2005.[3] R-phrases are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations. ... S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. ... The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with air. ... The explosive limit of a gas or a vapour, is the limiting concentration (in air) that is needed for the gas to ignite and explode. ... The autoignition temperature, or the ignition temperature of a substance is the lowest temperature at which a chemical will spontaneously ignite in a normal atmosphere, without an external source of ignition, such as a flame or spark. ... This page provides supplementary chemical data on ethylene. ... This page provides supplementary chemical data on ethylene. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... The relative dielectric constant of a material under given conditions is a measure of the extent to which it concentrates electrostatic lines of flux. ... This page provides supplementary chemical data on ethylene. ... This page provides supplementary chemical data on ethylene. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... It has been suggested that NMR Data Processing be merged into this article or section. ... Mass spectrometry (also known as mass spectroscopy (deprecated)[1] or in common speech mass-spec) is an analytical technique used to measure the mass-to-charge ratio of ions. ... The chemical structure of ethylene, the simplest alkene. ... Propylene, also known as propene, is a colorless flammable gas with chemical formula C3H6 having a garlic odor. ... Butylene, also known as butene, is the name of the three isomeric hydrocarbon gases with chemical formula C4H8. ... Ethane is a chemical compound with chemical formula C2H6. ... Acetylene (systematic name: ethyne) is the simplest alkyne hydrocarbon, consisting of two hydrogen atoms and two carbon atoms connected by a triple bond. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... The International Union of Pure and Applied Chemistry (IUPAC) is an international non-governmental organization devoted to the advancement of chemistry. ... A chemical compound is a chemical substance consisting of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... The chemical structure of ethylene, the simplest alkene. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy...

Contents

Structure

This hydrocarbon has four hydrogen atoms bound to a pair of carbon atoms that are connected by a double bond. All six atoms that comprise ethylene are coplanar. The H-C-H angle is 117°, close to the 120° for ideal sp2 hybridized carbon. The molecule is also relatively rigid: rotation about the C-C bond is a high energy process that requires breaking the π-bond, while retaining the σ-bond between the carbon atoms. Hydrocarbons are refined at oil refineries and processed at chemical plants A hydrocarbon is a chemical compound that consists only of the elements carbon (C) and hydrogen (H). ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle still characterizing a chemical element. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ... Covalent bonding is a form of chemical bonding characterized by the sharing of one or more pairs of electrons between atoms, in order to produce a mutual attraction, which holds the resultant molecule together. ... An angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle. ... This article or section contains information that has not been verified and thus might not be reliable. ...


The double bond is a region of high electron density, and most reactions occur at this double blond person. Electron density is the measure of the probability of an electron being present at a specific location. ...


History

From 1795 on, ethylene was referred to as the olefiant gas (oil-making gas), because it combined with chlorine to produce the oil of the Dutch chemists (1,2-dichloroethane), first synthesized in 1795 by a collaboration of four Dutch chemists. 1795 was a common year starting on Thursday (see link for calendar). ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... The chemical compound 1,2-dichloroethane, commonly known by its old name of ethylene dichloride (EDC), is a chlorinated hydrocarbon, mainly used to produce vinyl chloride monomer (VCM, chloroethene), the major precursor for PVC production. ...


In the mid-19th century, the suffix -ene (an Ancient Greek root added to the end of female names meaning "daughter of") was widely used to refer to a molecule or part thereof that contained one fewer hydrogen atoms than the molecule being modified. Thus, ethylene (C2H4) was the "daughter of ethyl" (C2H5). The name ethylene was used in this sense as early as 1852. Ethyl is a two-carbon substituent in organic chemistry. ... 1852 was a leap year starting on Thursday (see link for calendar). ...


In 1866, the German chemist Augustus von Hofmann proposed a system of hydrocarbon nomenclature in which the suffixes -ane, -ene, -ine, -one, and -une were used to denote the hydrocarbons with 0, 2, 4, 6, and 8 fewer hydrogens than their parent alkane[1]. In this system, ethylene became ethene. Hofmann's system eventually became the basis for the Geneva nomenclature approved by the International Congress of Chemists in 1892, which remains at the core of the IUPAC nomenclature. However, by that time, the name ethylene was deeply entrenched, and it remains in wide use today, especially in the chemical industry. 1866 (MDCCCLXVI) is a common year starting on Monday of the Gregorian calendar or a common year starting on Wednesday of the 12-day-slower Julian calendar. ... Chemical structure of methane, the simplest alkane Alkanes are chemical compounds that consists only of the elements carbon (C) and hydrogen (H) (i. ... 1892 (MDCCCXCII) was a leap year starting on Friday (see link for calendar). ... The International Union of Pure and Applied Chemistry (IUPAC) is an international non-governmental organization devoted to the advancement of chemistry. ...


IUPAC nomenclature rules make an exception for retaining the non-systematic "ethylene" name. [4]


Production

Ethylene is produced in the petrochemical industry by steam cracking. In this process, gaseous or light liquid hydrocarbons are briefly heated to 750–950 °C, inducing numerous free radical reactions. Generally, in these reactions, large hydrocarbons break down into smaller ones and saturated hydrocarbons become unsaturated. The result of this process is a complex mixture of hydrocarbons in which ethylene is one of the principal components. The mixture is separated by repeated compression and distillation. Petrochemicals are chemical products made from raw materials of petroleum (hydrocarbon) origin. ... In petroleum geology and chemistry, cracking is the process whereby complex organic molecules (e. ... In chemistry free radicals are uncharged atomic or molecular species with unpaired electrons or an otherwise open shell configuration. ... Vapours of hydrogen chloride in a beaker and ammonia in a test tube meet to form a cloud of a new substance, ammonium chloride A chemical reaction is a process that results in the interconversion of chemical substances. ... Physical compression is the result of the subjection of a material to compressive stress, resulting in reduction of volume. ... Laboratory distillation set-up using, without a fractionating column 1: Heat source 2: Still pot 3: Still head 4: Thermometer/Boiling point temperature 5: Condenser 6: Cooling water in 7: Cooling water out 8: Distillate/receiving flask 9: Vacuum/gas inlet 10: Still receiver 11: Heat control 12: Stirrer speed...


In another process used in oil refineries, large hydrocarbon molecules are "cracked" into smaller ones. Zeolite catalyst allows the cracking to be achieved at a lower temperature. Zeolite The micro-porous molecular structure of a zeolite, ZSM-5 Zeolites (Greek, zein, to boil; lithos, a stone) are minerals that have a micro-porous structure. ...


Theoretical considerations

Although ethylene is a relatively simple molecule, its spectrum[5] is considered to be one of the most difficult to explain adequately from both a theoretical and practical perspective. For this reason, it is often used as a test case in computational chemistry. Of particular note is the difficulty in characterizing the ultraviolet absorption of the molecule. Interest in the subtleties and details of the ethylene spectrum can be dated back to at least the 1950s. Extremely high resolution spectrum of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of matter and its properties by investigating light, sound, or particles that are emitted, absorbed or scattered by the matter under investigation. ... Computational chemistry is a branch of chemistry that uses the results of theoretical chemistry incorporated into efficient computer programs to calculate the structures and properties of molecules and solids, applying these programs to real chemical problems. ...


Chemical reactions

Additions to double bond

Like most alkenes, ethylene reacts with halogens to produce halogenated hydrocarbons1,2-C2H4X2. It can also react with water to produce ethanol, but the rate at which this happens is very slow unless a suitable catalyst, such as phosphoric or sulfuric acid, is used. Under high pressure, and, in the presence of a catalytic metal (platinum, rhodium, nickel), hydrogen will react with ethylene. The halogens or halogen elements are a series of nonmetal elements from Group 17 (old-style: VII or VIIA; Group 7 IUPAC Style) of the periodic table, comprising fluorine, F, chlorine, Cl, bromine, Br, iodine, I, and astatine, At. ... Ethanol, also known as ethyl alcohol, drinking alcohol or grain alcohol, is a flammable, colorless, slightly toxic chemical compound with a distinctive perfume-like odor, and is the alcohol found in alcoholic beverages. ... It has been suggested that this article or section be merged into Catalysis. ... Phosphoric acid, also known as orthophosphoric acid or phosphoric(V) acid, is an inorganic mineral acid having the chemical formula H3PO4. ... Sulfuric acid, H2SO4, is a strong mineral acid. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... General Name, Symbol, Number rhodium, Rh, 45 Chemical series transition metals Group, Period, Block 9, 5, d Appearance silvery white metallic Atomic mass 102. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Atomic mass 58. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...


Ethylene is used primarily as an intermediate in the manufacture of other chemicals used in the synthesis of monomers. Ethylene can be chlorinated to produce 1,2-dichloroethane (ethylene dichloride), which can be converted to vinyl chloride, the monomer precursor to plastic polyvinyl chloride, or combined with benzene to produce ethylbenzene, which is used in the manufacture of polystyrene, another important plastic. In chemistry, a monomer (from Greek mono one and meros part) is a small molecule that may become chemically bonded to other monomers to form a polymer. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... The chemical compound 1,2-dichloroethane, commonly known by its old name of ethylene dichloride (EDC), is a chlorinated hydrocarbon, mainly used to produce vinyl chloride monomer (VCM, chloroethene), the major precursor for PVC production. ... Vinyl chloride, also known as chloroethene in IUPAC nomenclature, is an important industrial chemical chiefly used to produce its polymer, polyvinyl chloride (PVC). ... Polyvinyl chloride PVC, (IUPAC Polychloroethene) commonly abbreviated PVC, is a widely used thermoplastic polymer. ... Benzene, also known as benzol, is an organic chemical compound with the formula C6H6. ... Chemical Structure of Ethylbenzene Ethylbenzene is an organic chemical compound which is an aromatic hydrocarbon with the chemical formula C8H10. ... Polystyrene is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum by the chemical industry. ...


Ethylene is more reactive than any alkanes because of two reasons:


1. It has a double bond, one called the π-bond(pi) and one called the σ-bond (sigma). Where π-bond is weak and σ-bond is strong. The presence of the π-bond makes it a high energy molecule. Thus bromine water decolourises readily.


2. High electron density at the double bond makes it react readily. It is broken in an addition reaction to produce many useful products. An addition reaction, in chemistry, is in its simplest terms an organic reaction where two or more molecules combine to form a larger one. ...


Oxidation

Ethylene is oxidized to produce ethylene oxide, which is hydrolysed to ethylene glycol. It is also a precursor to vinyl acetate. The most fundamental reactions in chemistry are the redox processes. ... The chemical compound ethylene oxide is an important industrial chemical used as an intermediate in the production of ethylene glycol and other chemicals, and as a sterilant for foodstuffs and medical supplies. ... This article needs to be wikified. ...

Main article: Wacker process

Ethylene undergoes oxidation by palladium to give acetaldehyde. This conversion was at one time a major industrial process.[6] The process proceeds via the initial complexation of ethylene to a Pd(II) center. The Wacker process or the Hoechst-Wacker process (named after the chemical companies of the same name) originally referred to the oxidation of ethylene to acetaldehyde by oxygen in the presence of a palladium(II) chloride catalyst. ... R-phrases , , S-phrases , , , Flash point −39 °C Autoignition temperature 185 °C RTECS number AB1925000 Supplementary data page Structure and properties n, εr, etc. ...


In the synthesis of fine chemicals

Ethylene is useful in organic synthesis.[7] Representative reactions include Diels-alder additions, ene reaction, and arene alkylation. Organic synthesis is the construction of organic molecules via chemical processes. ... Ene reactions are Group transfer reactions between an alkyne or alkene, or similar double bonded species and an allyl-like species. ...


Polymerization

Main article: Ziegler-Natta catalyst

Ethylene polymerizes to produce polyethylene, also called polyethene or polythene, the world's most widely-used plastic. A Ziegler-Natta catalyst is a reagent used in the production of unbranched, stereoregular vinyl polymers. ... A polymer is a substance composed of molecules with large molecular mass consisting of repeating structural units, or monomers, connected by covalent chemical bonds. ... This article or section does not cite its references or sources. ...


Miscellaneous

Ethylene was once used as a general anesthetic applicable via inhalation, but it has long since been replaced. Anesthesia (AE), also anaesthesia (BE), is the process of blocking the perception of pain and other sensations. ...


It has also been hypothesized that ethylene was the catalyst for utterances of the oracle at Delphi in ancient Greece.Template:See Broad, Wm. J. (2006) The Oracle. New York ISBN 1-59420-081-5 Consulting the Oracle by John William Waterhouse, showing eight priestesses in a temple of prophecy An oracle is a person or persons considered to be the source of wise counsel or prophetic opinion; an infallible authority, usually spiritual in nature. ... Delphi (Greek Δελφοί, [ðe̞lˈfi]) is an archaeological site and a modern town in Greece on the south-western spur of Mount Parnassus in a valley of Phocis. ...


It is also found in many lip gloss products.


Production of Ethylene in mineral oil filled transformers is a key indicator of severe localized overheating (>750 degrees C.)


Ethylene as a plant hormone

Ethylene acts physiologically as a hormone in plants.[8][9]. It exists as a gas and acts at trace levels throughout the life of the plant by stimulating or regulating the ripening of fruit, the opening of flowers, and the abscission (or shedding) of leaves. Its biosynthesis starts from methionine with 1-aminocyclopropane-1-carboxylic acid (ACC) as a key intermediate. Plant hormones (or plant growth regulators, or PGRs) are internally-secreted chemicals in plants that are used for regulating the plants growth. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta—liverworts Anthocerotophyta—hornworts Bryophyta—mosses Vascular plants (tracheophytes) †Rhyniophyta—rhyniophytes †Zosterophyllophyta—zosterophylls Lycopodiophyta—clubmosses †Trimerophytophyta—trimerophytes Pteridophyta—ferns and horsetails Seed plants (spermatophytes) †Pteridospermatophyta—seed ferns Pinophyta—conifers Cycadophyta—cycads Ginkgophyta—ginkgo Gnetophyta—gnetae Magnoliophyta—flowering plants... Ripening is a process in fruit that causes them to become more edible. ... For other uses, see Fruit (disambiguation). ... A Phalaenopsis flower Rudbeckia fulgida A flower, (<Old French flo(u)r<Latin florem<flos), also known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). ... Abscission (from ab- away from, and scission cutting or severing) is the shedding of a body part. ... Leaves are an Icelandic five-piece alternative rock band who came to prominence in 2002 with their debut album, Breathe, drawing comparisons to groups such as Coldplay and Doves. ... Methionine (Met, M. C5H11NO2S) is an essential nonpolar amino acid, and a lipotropic. ... 1-Aminocyclopropane-1-carboxylic acid (ACC) is a disubstituted cyclic amino acid. ...


It has been shown that ethylene is produced from essentially all parts of higher plants, including leaves, stems, roots, flowers, fruits, tubers, and seedlings. It is commercially used in the horticulture industry to hasten the ripening of bananas, or inducing flowering of bromeliads. However, in some cases it may be detrimental by reducing the shelf life of some products such as flowers, pot plants, or kiwi fruit.


"Ethylene has been used in practice since the ancient Egyptians, who would gas figs in order to stimulate ripening. The ancient Chinese would burn incense in closed rooms to enhance the ripening of pears. In 1864, it was discovered that gas leaks from street lights led to stunting of growth, twisting of plants, and abnormal thickening of stems (the triple response)[see plant senescence](Arteca, 1996; Salisbury and Ross, 1992). In 1901, a Russian scientist named Dimitry Neljubow showed that the active component was ethylene (Neljubow, 1901). Doubt discovered that ethylene stimulated abscission in 1917 (Doubt, 1917). It wasn't until 1934 that Gane reported that plants synthesize ethylene (Gane, 1934). In 1935, Crocker proposed that ethylene was the plant hormone responsible for fruit ripening as well as inhibition of vegetative tissues (Crocker, 1935). Incense is a preparation of aromatic plant matter, often with the addition of essential oils extracted from plant or animal sources, intended to release fragrant smoke for religious, therapeutic, or aesthetic purposes as it smolders. ... Plant senescence is a heavily studied subject just as it is in the other kingdoms of life. ... Abscission (from ab- away from, and scission cutting or severing) is the shedding of a body part. ...


Because Nicotiana benthamiana leaves are susceptible to injuries, they are used in plant physiology practicals to study ethylene secretion. Binomial name Nicotiana benthamiana Nicotiana benthamiana is a close relative of tobacco and species of nicotiana indigenous to Australia. ...

Image File history File links Information_icon. ...

Ethylene biosynthesis in plants

All plant tissues are able to produce ethylene, although the production rate is normally low.

"Ethylene production is regulated by a variety of developmental and environmental factors. During the life of the plant, ethylene production is induced during certain stages of growth such as germination, ripening of fruits, abscission of leaves, and senescence of flowers. Ethylene production can also be induced by a variety of external aspects such as mechanical wounding, environmental stresses, and certain chemicals including auxin and other regulators" [10]

The biosynsthesis of the hormone starts with conversion of the aminoacid methionine to S-adenosyl-L- methionine (SAM, also called Adomet) by the enzyme Met Adenosyltransferase. SAM is then converted to 1-aminocyclopropane-1-carboxylic-acid (ACC) by the enzyme ACC synthase (ACS); the activity of ACS is the rate-limiting step in ethylene production, therefore regulation of this enzyme is key for the ethylene biosynthesis. The final step requires oxygen and involves the action of the enzyme ACC-oxidase (ACO), formerly known as the Ethylene Forming Enzyme (EFE).


The pathway can be represented as follows:

 Methionine --> SAM --> ACC --> Ethylene 

Ethylene biosynthesis can be induced by endogenous or exogenous ethylene. ACC synthesis increases with high levels of auxins, specially Indol Acetic Acid (IAA), and cytokinins. ACC synthase is inhibited by abscisic acid.

Image File history File links Information_icon. ...

Environmental and biological triggers of ethylene

Environmental cues can induce the biosynthesis of the plant hormone. Flooding, drought, chilling, wounding, and pathogen attack can induce the ethylene formation in the plant.


In flooding, root suffers from anoxia, leading to the synthesis of the 1-Aminocyclopropane-1-carboxylic acid(ACC). As it lacks of oxygen, ACC is transported upwards in the plant and then oxidized in leaves. The product, the ethylene causes the epinasty of the leaves. Asphyxia is a condition of severely deficient supply of oxygen to the body. ... 1-Aminocyclopropane-1-carboxylic acid (ACC) is a disubstituted cyclic amino acid. ...

Image File history File links Information_icon. ...

Physiological responses of plants

The internal development of the plant can enhance the biosynthesis of the plant hormones. Germination can induce the synthesis of the plant hormone; it is to enhance the formation of active gibberellin for the stimulation of the enzymes in germination. Ethylene is synthesized in the ripening fruits and the senescent leaf and flowers.


For the climacteric fruit, the respiration rate and also the ethylene formation are sharply increased. Menopause (also known as the Change of life or climacteric) is a stage of the human female reproductive cycle that occurs as the ovaries stop producing estrogen, causing the reproductive system to gradually shut down. ...


In pollination, when the pollen reaches the stigma, the precursor of the ethylene, ACC, is secreted to the petal, the ACC releases ethylene with ACC oxidase. A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ... Look up stigma on Wiktionary, the free dictionary. ...

  • Synthesized in nodes of stems
  • Rapidly diffuses
  • Inhibiting effects of ethylene on shoot growth (more specifically on stem elongation) reduced in the presence of light. Also ethylene levels are decreased by light

Other plant responses: A stem is the main axis of a vascular plant that is divided into nodes and internodes and has one or more leaves or buds at the nodes. ... This article or section does not cite its references or sources. ... It has been suggested that this article or section be merged with Electromagnetic radiation. ...

  • Stimulates leaf and flower senescence
  • Induces leaf abscission mainly in older leaves.
  • Induces seed germination
  • Induces root hair growth – this increases the efficiency of water and mineral absorption
  • Stimulates epinasty – leaf petiole grows out, leaf hangs down and curls into itself
  • Stimulates fruit ripening
  • Induces the growth of adventitious roots during flooding
  • Affects neighboring individuals
  • Disease/wounding resistance
  • Triple response when applied to seedlings – root ? and shoot growth inhibition and pronounced hypocotyl hook bending
  • Inhibits stem swelling or Stimulates cell broadening and lateral root growth (some sources are in disagreement)
  • Interference with auxin transport (with high auxin concentrations)
  • Induces flowering in pineapples

It has been suggested that Longevity genes be merged into this article or section. ... It has been suggested that Germination rate be merged into this article or section. ... Interior structure of a trichome. ... Leaf of Dog Rose (Rosa canina), showing the petiole and two leafy stipules In botany, the petiole is the small stalk attaching the leaf blade to the stem. ... Ripening is a process in fruit that causes them to become more edible. ... Primary and secondary roots in a cotton plant In vascular plants, the root is that organ of a plant body that typically lies below the surface of the soil (compare with stem). ... Hypocotyl is a botanical term for a part of a germinating seedling of a seed plant. ... Binomial name Ananas comosus (L.) Merr. ...

Effects upon humans

Ethylene is colorless, has a pleasant sweet faint odor, and has a slightly sweet taste, and as it enhances fruit ripening, assists in the development of odour-active aroma volatiles (especially esters), which are responsible for the specific smell of each kind of flower or fruit. In high concentrations it can cause nausea. Its use in the food industry to induce ripening of fruit and vegetables, can lead to accumulation in refrigerator crispers, accelerating spoilage of these foods when compared with naturally ripened products. General formula of a carboxylate ester. ...


Ethylene has long been in use as an inhalatory anaesthetic. It shows little or no carcinogenic or mutagenic properties, and although there may be moderate hyperglycemia, post operative nausea, whilst higher than nitrous oxide is less than in the use of cyclopropane. During the induction and early phases, blood pressure may rise a little, but this effect may be due to patient anxiety, as blood pressure quickly returns to normal. Cardiac arrythmias are infrequent and cardio-vascular effects are benign. Exposure at 37.5% for 15 minutes may result in marked memory disturbances. Humans exposed to as much as 50% ethylene in air, whereby the oxygen availability is decreased to 10%, experience a complete loss of consciousness and may subsequently die. Effects of exposure seem related to the issue of oxygen deprivation. Layers of Atmosphere (NOAA) Air redirects here. ...


In mild doses, ethylene produces states of euphoria, associated with stimulus to the pleasure centres of the human brain. It has been hypothesised that human liking for the odours of flowers is due in part to a mild action of ethylene associated with the plant. Many geologists and scholars believe that the famous Greek Oracle at Delphi (the Pythia) went into her trance-like state as an affect of ethylene rising from ground faults.[11] Delphi (Greek Δελφοί, [ðe̞lˈfi]) is an archaeological site and a modern town in Greece on the south-western spur of Mount Parnassus in a valley of Phocis. ... Aegeus, a mythical king of Athens, consults the Pythia, who sits on a tripod. ...


STAGE 1) INDIFFERENCE

  • Percent of O2 Saturation at 90%
  • Night vision decreased
  • Mild euphoria reported.

STAGE 2) COMPENSATION

  • Percent of O2 Saturation at 82 to 90%
  • Respiratory rate has compensatory increase
  • Pulse, also a compensatory increase
  • Night vision is decreased further, focus is simplified
  • Performance ability is somewhat reduced, mild distortion to speech, utterances increasingly ambiguous.
  • General Alertness level is somewhat reduced to anything but central concerns
  • Symptoms may begin in those patients with pre-existing significant cardiac, pulmonary, or hematologic diseases.
  • Euphoria

STAGE 3) DISTURBANCE

  • Percent of O2 Saturation at 64 to 82%
  • Compensatory mechanisms increasingly become inadequate
  • Air hunger, gasping for breath
  • Fatigue, lassitude, inability to maintain balance
  • Tunnel Vision, out-of-body experiences
  • Dizziness
  • Mild to Persistent Headache
  • Belligerence, certainty of truth
  • Extreme Euphoria, belief in capacities of the self enhanced
  • Visual acuity is reduced, dreamlike seeing of visions
  • Numbness and tingling of extremities
  • Hyperventilation
  • Distortions of judgement, abnormal or illogical inferences drawn
  • Memory loss after event
  • Increased Cyanosis
  • Decreased ability for escape from toxic environment

STAGE 4) CRITICAL DISTURBANCE

  • Percent of O2 Saturation at 60 to 70% or less
  • Further deterioration in judgement and coordination may occur in 3 to 5 minutes or less
  • Total incapacitation and unconsciousness follow rapidly

In air, ethylene acts primarily as an asphyxiant. Concentrations of ethylene required to produce any marked physiological effect will reduce the oxygen content to such a low level that life cannot be supported. For example, air containing 50% of ethylene will contain only about 10% oxygen.


Loss of consciousness results when the air contains about 11% of oxygen. Death occurs quickly when the oxygen content falls to 8% or less. There is no evidence to indicate that prolonged exposure to low concentrations of ethylene can result in chronic effects. Prolonged exposure to high concentrations may cause permanent effects because of oxygen deprivation.


Ethylene has a very low order of systemic toxicity. When used as a surgical anaesthetic, it is always administered with oxygen with an increased risk of fire. In such cases, however, it acts as a simple, rapid anaesthetic having a quick recovery. Prolonged inhalation of about 85% in oxygen is slightly toxic, resulting in a slow fall in the blood pressure; at about 94% in oxygen, ethylene is acutely fatal.


References

  1. ^ The Merck Index" 13th Edition, Merck & Co, Whitehouse Station, NJ. 2001. ISBN 0-911910-13-1
  2. ^ Wang K, Li H, Ecker J. "Ethylene biosynthesis and signaling networks.". Plant Cell 14 Suppl: S131-51. PMID 12045274.
  3. ^ “Production: Growth is the Norm” Chemical and Engineering News, July 1 0, 2006, p. 59.
  4. ^ IUPAC nomenclature rule A-3.1 The following non-systematic names are retained: Ethylene H2C=CH2
  5. ^ Ethylene:UV/Visible Spectrum. NIST Webbook. Retrieved on 2006-09-27.
  6. ^ Elschenbroich, C.;Salzer, A. ”Organometallics : A Concise Introduction” (2nd Ed) (2006) Wiley-VCH: Weinheim. ISBN 3-527-28165-7
  7. ^ Crimmins, M. T.; Kim-Meade, A. S. "Ethylene" in Encyclopedia of Reagents for Organic Synthesis (Ed: L. Paquette) 2004, J. Wiley & Sons, New York. DOI: 10.1002/047084289.
  8. ^ Chow B, McCourt P (2006). "Plant hormone receptors: perception is everything.". Genes Dev 20 (15): 1998-2008. PMID 16882977.
  9. ^ De Paepe A, Van der Straeten D (2005). "Ethylene biosynthesis and signaling: an overview.". Vitam Horm 72: 399-430. PMID 16492477.
  10. ^ Yang, S. F., and N. E. Hoffman P (1984). "Ethylene biosynthesis and its regulation in higher plants.". Ann. Rev. Plant Physiol. 35: 155-89.
  11. ^ John Roach. "Delphic Oracle's Lips May Have Been Loosened by Gas Vapors", National Geographic, August 14, 2001. Retrieved on March 8, 2007

For the Manfred Mann album, see 2006 (album). ... September 27 is the 270th day of the year (271st in leap years) in the Gregorian calendar. ...

External links


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