BIOSYNTHESIS OF ALCOHOL

Alcohol is often used to refer to ethanol, also called grain alcohol, and sometimes for a drink containing alcohol. This is because ethanol is used as a base for the drink, rather than methanol, or other alcohol group. So is the alcohol used in the world famasi. Alcohol is meant ethanol. Actual alcohol in chemistry has a wider meaning. Alcohol is a compound derived from an alkane by substituting one or more hydrogen atoms with a hydroxyl group (OH).B. Classification of alcoholAlcohol can be divided into several groups depending on how the position of the-OH group in the chain of carbon atoms. Each alcohol group also has some chemical differences.A. According to the C atom that binds to the OH group1.1 Primary AlcoholIn the primary alcohols (1 °), the carbon atom carrying the-OH group attached to only one alkyl group.Some examples of primary alcohols, among others:In the example above, there is only one bond between the group CH2yang the-OH group with an alkyl group.There are exceptions to methanol, CH3OH, where methanol is considered as a primary alcohol even though there are no alkyl groups attached to the carbon atom carrying the-OH group.1.2 Secondary AlcoholIn the secondary alcohol (2 °), the carbon atom that binds to the-OH group is attached directly to two alkyl groups, the alkyl group may be the same or different.Example:1.3 tertiary alcoholAt the tertiary alcohol (3 °) carbon atom that binds to the-OH group attached directly to three alkyl groups, which may be any combination of the same or different alkyl.Example:2. According to the OH group that binds2.1 Alcohol is an aliphaticAliphatic alcohols are liquids that are highly influenced by hydrogen bonding. With increasing chain length, the influence of the polar hydroxyl groups on the molecular properties decreased. Properties such as water molecules are reduced, the opposite is more like hydrocarbons. As a result of low molecular weight alcohol tends to dissolve in water, whereas high-molecular-weight alcohol is not the case. Alcohol boils at a temperature high enough. As a group of compounds, phenol has a boiling point and solubility are highly variable, depending on the nature subtituen attached to the benzene ring (Petrucci, 1987).2.2 Aromatic Alcohol3. According to the OH group3.1 Alcohol monovalentMonovalent alcohol is alcohol which has only one functional group-OH.Example: Ethanol, Proponal3.2 Alcohol divalent / Alkanadiol       Divalent alcohol is alcohol which has two hydroxyl groups.3.3 Alcohol trivalent / Alkanatriol       Trivalent alcohol is alcohol having three hydroxyl groups.3.4 Alcohol polyvalent / polyhydroxy alcoholAlcohol is a type of compound polyvalent alcohol having an OH group is more than one structure.Example: Etanadiol, Propanatriol (glycerol)C. Properties of alcoholBoiling pointBoiling points of some simple primary alcohols having up to 4 carbon atoms.Namely:Primary alcohols are compared with the equivalent alkanes (methane to butane), which has the same number of carbon atoms.From the graph above it can be observed that:• a boiling point of alcohol is always much higher than the alkane having the same number of carbon atoms.• Boiling point of alcohol increases with increasing number of carbon atoms.Boiling point patterns reflect the patterns of inter-molecular attractive force.Hydrogen bondsHydrogen bonding occurs between molecules in which a hydrogen atom bonded to one of the very electronegative elements - fluorine, oxygen or nitrogen.For alcohol, there are hydrogen bonds between the hydrogen atoms are slightly positively charged with the lone pairs on oxygen in the other molecules.Hydrogen atoms are slightly positively charged because the electrons attracted away from the hydrogen bond to the oxygen atoms are highly electronegative.In the alkanes, the only intermolecular forces that exist are the van der Waals dispersion forces. Hydrogen bonds are much stronger than the forces so that it takes more energy to separate molecules of alcohol than to separate the alkane molecules. This has a major reason why the boiling point of alcohol is higher than the alkanes.The influence of van der Waals forceInfluence on the boiling point of alcohol:Hydrogen bond is not the only intermolecular forces in alcohol. The alcohol was found also dispersion forces van der Waals and dipole-dipole interaction. Hydrogen bonding and dipole-dipole interaction is almost the same for all the alcohol, but the dispersion forces increases when alcohol becomes larger. These attractions become stronger if the molecules are longer and have more electrons. This increases the amount of temporary dipoles are formed.This is the reason why the boiling point increases as the number of carbon atoms in the chain increases. It takes more energy to eliminate the dispersion forces, so that the boiling point increases.Influence on the comparison between the alkane and alcohol:Even if there is no hydrogen bonding or dipole-dipole interactions, the boiling point of alcohol would be higher than the corresponding alkane having the same number of carbon atoms.Compare between ethane and ethanol:Ethanol has a longer molecule, and oxygen contained in the molecule provides an additional 8 electrons. Structure that is longer and the oxygen atom increases the magnitude of van der Waals dispersion forces, so the boiling point.Alcohol solubility in waterSmall alcohols dissolve completely in water. However comparison of the volume that we make, the mixture will still be one solution.However, the solubility decreases with increasing hydrocarbon chain length in the alcohol. If the carbon atom to achieve four or more, decrease its solubility is very clearly visible, and the mixture may not converge.Small solubility of alcohols in waterOn pure ethanol and pure water to be mixed, inter-molecular attractive force main that there is hydrogen bonding.To be able to mix the two solutions, the hydrogen bonds between water molecules and hydrogen bonds between ethanol molecules must be broken. Termination of this hydrogen bond energy needs.However, if the molecules are mixed, the hydrogen bonds that will be formed between water molecules with molecules of ethanol.The energy released when hydrogen bonds are formed more or less new to offset the energy needed to break the bonds earlier.In addition, disturbances in the system increases, the entropy increases. This is another factor that determines whether the pooling solution is going to happen or not.D. The use of alcoholAlcohol is used as, among others: organic solvents, synthesis of other compounds, disinfectant, detergent raw materials, bakterisid, methanol is used to mendenaturasikan ethanol, 2-propanol to make acetone, kloreton for preservatives, glycols can be as explosive substances, gliseron for raw materials soap.E. Synthesis of alcoholOxidation / combustion of AlcoholAll the carbon compounds that react with oxygen in sufficient quantity is often known by the complete combustion reaction will produce the final result of CO2 and H2O. whereas the reaction of incomplete combustion (lack of oxygen) of CO2 will not be formed but CO will be formed. so that the alcohol oxidation reaction also produces CO2 and H2O the final result, for example:However, this oxidation reaction actually consists of several steps that the results vary. It can be used to distinguish the types of alcohol. The reaction is:A. Primary alcohol will go through two stages in the first phase will produce aldehydes / alkanal, then again when oxidized to produce acids karbosilat.             2. Secondary alcohol is going through a stage of producing ketone / alkanon3. Tertiary alcohol oxidation reaction can not occurThe dehydration reaction with H2SO4 at high temperatures will release air/H2O with two types of reactions based on the temperature:• at a temperature of 130 - 140oC would yield ethers• at a temperature of 170 - 180 ° C will produce alkenesAlcohol with a carboxylic acid ester will yield, the reaction is called esterification.Reaction - a reaction to alcohol:A. Alcohol can react with Na metal to form H22. Alcohol can react with concentrated HCl produces H2OIn the reaction with metal substitution Na Na occur with a bound H O and H 2 yield while the reaction with HCl occurs at the OH group with Cl substitution and produce H2O.3. Alcohol can react with PCl3 and PCL5Alkanal / aldehydes when reduced with H2 yield of primary alcoholH2 reduction reaction of ketones with secondary alcohol producesF. Alcohol biosynthesisBiosynthesis is the formation of naturally occurring molecules in the cell of another, less complicated molecular structure, through the reaction endeorganik. Biosynthesis process will last a very complex, depending on the kinds of enzymes that are available so that similar plants that grow in different areas it is possible to have a certain metabolite formation pathways are not identical (the phenomenon of "vikarias: Chemical-Ras).Fermentation is one example of the process of biosynthesis. Fermentation is the process of energy production in cells in keadaananaerobik (without oxygen). Sugar is a common ingredient in the fermentation. Some examples of fermentation are ethanol, lactic acid, and hydrogen. However, some other components may also be produced from the fermentation such as butyric acid and acetone. Yeast is known as a material commonly used in fermentation to produce ethanol in beer, wine and other alcoholic beverages. Anaerobic respiration in mammalian muscle during the hard work (which has no external electron acceptor), can be categorized as a form of fermentation that produces lactic acid as a by-product. This accumulation of lactic acid that plays a role in causing muscle fatigue.Fermentation reactions in different ways depending on the type of sugar used and the resulting product. Briefly, glucose (C6H12O6) which is the simplest sugar, through fermentation will produce ethanol (2C2H5OH). The reaction was carried out by yeast fermentation, and is used in food production.Chemical reaction equationsC6H12O6 → 2CO2 + 2 + 2C2H5OH ATP (energy released: 118 kJ per mole)      Described asSugars (glucose, fructose, or sucrose) → Alcohol (ethanol) + carbon dioxide + energy (ATP)B.1 Alcohol FermentationSome organisms such as Saccharomyces can live in both environmental conditions and lack of oxygen sufficient oxygen. Such organisms are called facultative aerobes. In case of insufficient oxygen, Saccharomyces will conduct regular respiration. However, if the state would do less environmental oksigenSaccharomyces fermentation. In an anaerobic, pyruvic acid produced by glycolysis is converted to acetic acid and CO2. Furthermore, acetic acid is converted into alcohol. The process of changing the acetic acid into alcohol followed by changes in NADH into NAD +. With the formation of NAD +, glycolysis event could happen again. In this alcoholic fermentation, of one mole of glucose can be produced only two molecules of ATP. Alcoholic fermentation, in a simple, proceeds as follows.In some microbial energy release events take place because of pyruvic acid is converted to acetic acid + acetic acid diabah selanjutaya CO2 into alcohol. In alcohol fermentation, one molecule of glucose can only produce 2 ATP molecules, compared with aerobic respiration, one molecule of glucose can produce 38 molecules of ATP.His reaction:A. Sugar (C6H12O6) ----> pyruvic acid (glycolysis)2. Dekarbeksilasi pyruvic acid.Asampiruvat --------------> CO2 + acetaldehyde.pyruvate decarboxylase (CH3CHO)3. Acetaldehyde by alcohol dihidrogenase converted into alcohol (ethanol).2 CH3CHO + 2 NADH2 ---------> 2 + 2 NAD C2HsOH                                     Alcohol dehydrogenase enzymeSummary of reactions:C6H12O6 -----> 2 C2H5OH + 2 CO2 + 2 NADH2 + EnergyAs in the case of lactic acid fermentation, this reaction is a waste. Most of the energy contained in glucose is still present in the ethanol, because ethanol is often used as engine fuel. These reactions, like lactic acid fermentation, is also dangerous. Yeast can poison themselves if the ethanol concentration reached 13% (This explains the maximum levels of alcohol in fermented beverages such as wine).Alcoholic products are extremely diverse ranging from food to energy. Food products of the longest known is the wine and beer. Microorganisms are involved mainly yeasts of the genus Saccharomyces sp. The most widely used Saccharomyces is S. cerevisiae and S. carlbergensis. This yeast will convert sugar into alcohol substrates in aerobic conditions. If the yeast is grown in aerobic atmosphere it will produce more cells than its metabolites, and is used for the production of baker's yeast.B.2 Fermented MilkSome fermented milk containing alcohol, among others, kefir and koumiss. Kefir is a fermented milk containing alcohol 0.5% - 1%. The bacteria that causes the formation of alcohol is kefir and Torula kefir Sacharomycfes. On koumiss, the alcohol content is higher again. This product contains alcohol by 1% - 2.5%. Microbes are added and the alcohol is causing Torulla colmic.B.3 Cane Molasses FermentationAlcohol 96% is a byproduct of the sugar cane industry. In the liquid sugar (Nira) glucose only kind that can be crystallized saccharose into sugar. Glucose while others even sweeter taste but can not crystallized sugar called glucose reduction or rupture, glucose is utilized by the type of sugar to be fermented into alcohol. Microorganisms type "Sacaromyces Cerevicae" are often used for this fermentation, which produces 7 different microbial enzymes catalyze the reaction.Reaction:C6H12O6 =======> 2C2H5OH + 2CO2 + Energy.-------------- À Glucose EthanolAlcohol produced from the fermentation process the results are still low levels (below 12%) that is processed in stages in order to produce distilled alcoholic strength 96%. Besides the alcohol kind of "ethanol" (C2H5OH) also contained a small portion of alcohol type "methanol" (CH3OH), methanol is highly toxic to humans so as not to drink the blue CuSO4 was added, the market we are familiar with the name methylated.B.4 Wine FermentationYeast is doing fementasi mikrooorganisme fruit juice into wine. Commonly used in yeast fermentation is Saccharomyces sp. This yeast will convert sugar into alcohol and CO2. In this reshuffle is also necessary nutrients that support growth of yeast, if not available on raw materials. Dtambahkan common ingredient is ammonium phosphate as nitrogen source.a. Fermentation ProcessFermentation is the process by which wine grape juice together with other material altered by biochemical reactions and produce wine yeasts. Material for fermentation is sugar plus yeast will produce alcohol and CO2. CO2 is released into the air from the mixture of wine and alcohol will remain in the fermentor. If all the fruit sugar is converted into alcohol or alcohol ingested approximately 15% is usually fermentation has been completed or terminated. During the fermentation is often added nitrogen and micro nutrients to prevent the production of H2S gas. If this gas appears to be causing an unpleasant smell.During fermentation, the resulting liquid is called "must". In order to prevent bacteria growth on the stirring must then be done. Must begin to bubble at the 8-20. Early stage of this fermentation process in red wine is 5-10 days, white wine 10-15 days. After this initial phase followed the second stage. In the second stage of fermentation, the wine was transferred to a fermenter should not enter the presence of oxygen. At this stage of alcohol will result in higher levels. Depending on the material used, the wine may taste sweeter or alcohol and this will affect the market price.b. Wine fermented with yeast teramobilisasiThe use of cell systems amobilitas by continuous fermentation of wine has become an interesting discussion. This system not only increases productivity but also improve bioprocess costs. Many types of bioreactors used in a continuous process, one of which is a packed-bed Bioreactors are popular because of low operating cost and easy operation. During the fermentation of alcoholic beverages, volatile compounds are also produced with various concentrations. These compounds have an important role in the properties and sensory flavor.c. Volatile compounds in wine fermentation of mangoThe smell of wine is the result of a complex combination of many components, especially the volatile compounds into penciri wine. At least there are 18 wine mango with various concentrations of volatile compounds. There are 8 potential as aroma compounds are: acetaldehyde, diethyl succinate, atil acetate, ethyl butyrate, isoamil alcohol, l-heksanol, ethyl decanoate and kaproat acid.d. Wine of the leatherbackStar fruit (Averrhoa carambola) can be made wine, but be aware of the level of sweetness (depending on the varieties of fruit) and fruit age. The materials used are of star fruit juice, sugar, lemon juice (to control acidity), pektat acid (pectin in the skin to remodel starfruit), yeast (Sachharomyces cerevisiae), nutrients and water. Fruit juice boiled with sugar and nutris then put in bottles and other materials added. Allow closed for 12 hours, add yeast enzyme pektat and then do an incubation for 12 hours for new active yeasts do ferment until the emergence of bubbles is complete. Aging can be done for 30 days or more to obtain a clear wine. Clear wine is then bottled and added vitamin C.Urungkan pengeditan