Glucose To Fructose Chemical Reaction

Glucose And Fructose To Platform Chemicals: Understanding The Thermodynamiclandscapes Of Acid-catalysed Reactions Using High-level Ab Initio Methods.

1. Phys Chem Chem Phys. 2012 Dec 28;14(48):16603-11. doi: 10.1039/c2cp41842h. Epub2012 Aug 29. Glucose and fructose to platform chemicals: understanding the thermodynamiclandscapes of acid-catalysed reactions using high-level ab initio methods. Assary RS(1), Kim T, Low JJ, Greeley J, Curtiss LA. (1)Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA. [email protected] Molecular level understanding of acid-catalysed conversion of sugar molecules to platform chemicals such as hydroxy-methyl furfural (HMF), furfuryl alcohol (FAL),and levulinic acid (LA) is essential for efficient biomass conversion. In thispaper, the high-level G4MP2 method along with the SMD solvation model is employedto understand detailed reaction energetics of the acid-catalysed decomposition ofglucose and fructose to HMF. Based on protonation free energies of varioushydroxyl groups of the sugar molecule, the relative reactivity of gluco-pyranose,fructo-pyranose and fructo-furanose are predicted. Calculations suggest that, in addition to the protonated intermediates, a solvent assisted dehydration of oneof the fructo-furanosyl intermediates is a competing mechanism, indicating thepossibility of multiple reaction pathways for fructose to HMF conversion inaqueous acidic medium. Two reaction pathways were explored to understand thethermodynamics of glucose to HMF; the first one is initiated by the protonationof a C2-OH group and the second one through an enolate intermediate involvingacyclic intermediates. Additionally, a pathway is proposed for the formation offurfuryl alcohol from glucose initiated by the protonation of a C2-OH position,which includes a C-C bond cleavage, and the formation of formic acid. Thedetailed free energy landscapes predicted in this study can be used as Continue reading >>

What Is The Difference In Structure Between Glucose And Fructose? - Quora

What is the difference in structure between glucose and fructose? Both are hexose sugars, i.e. have 6 carbons in their structure. However, glucose is an aldohexose, whereas fructose is a ketohexose. This means that the functional group present in these sugars is an aldehydic and a ketonic group respectively. I have highlighted the functional groups in these pictures of the linear structures of the two sugars. In nature, however, the linear chain structures exist in equilibrium with their cyclised forms. Here, another difference arises. Glucose forms a pyranose ring structure, whereas fructose makes a furan ring structure: Hence, glucose makes a six membered ring, and fructose makes a five membered ring. You can compare the ring structure with their linear chain structure here: Another difference is that in glucose, the anomeric carbon is the first carbon, whereas in fructose, the anomeric carbon is the second carbon. The anomeric carbon is the one containing the carbonyl group, which reacts to form the cyclised structure. 8.8k Views View Upvoters Not for Reproduction Originally Answered: What is the structure of fructose and glucose? Both fructose and glucose are 6 carbon (C6) hexoses but they have different structures. Other C6 sugars that humans can metabolize include mannose, trehalose and galactose Various 6 carbon sugars are able to enter glycolysis at various points. Sucrose is a dissachride of glucose and fructose while lactose is a disaacharide of glucose and galactose. This image shows structures of the major C6 sugars and how they are metabolized: 1. Galactose enters via a glycogen offshoot (Gal1P to G1P) . Two enzymes are involved; Galactose 1 phosphate UDP transferase (Gal1PUT) and Galactokinase. 2. Fructose kinase phosphorylates F to F1P 3. F1P aldolase (a Continue reading >>

Efficient Isomerization Of Glucose To Fructose Over Zeolites In Consecutive Reactions In Alcohol And Aqueous Media

Efficient Isomerization of Glucose to Fructose over Zeolites in Consecutive Reactions in Alcohol and Aqueous Media Centre for Catalysis and Sustainable Chemistry, Department of Chemistry, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark Chemical and Environmental Technology Department, Universidad Rey Juan Carlos, C/Tulipn s/n, E-28933 Mstoles, Madrid, Spain Cite This: J. Am. Chem. Soc.2013135145246-5249 Article Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days. Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts. The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Download Hi-Res Image Download to MS-PowerPoint Isomerization reactions of glucose were catalyzed by different types of commercial zeolites in methanol and water in two reaction steps. The most active catalyst was zeolite Y, which was found to be more active than the zeolites beta, ZSM-5, and mordenite. The novel reaction pathway involves glucose isomerization to fructose and subsequent reaction with methanol to form methyl fructoside (step 1), followed by hydrolysis to re-form fructose after water addition (step 2). NMR analysis with 13C-labeled sugars confirmed this reaction pathway. Conversion of glucose f Continue reading >>

Disaccharides

Disaccharides are formed by the condensation reactions of two simple sugar molecules. Condensation is the loss of water in a chemical reaction. Two OH groups, one from each sugar molecule, come together to release water and form an oxygen bridge between. One of the OH groups is attached to the anomeric carbon (the carbon that has 2 oxygens bonded to it). Here you see the formation of sucrose from the 6-membered form of glucose and the 5-membered form of fructose. Note that linear fructose has a ketone rather than an aldehyde group. Which carbon in glucose and in fructose would be the carbonyl carbon in the linear form? Another example is the condensation of 2 molecules of glucose. Sucrose is the disaccharide of glucose and fructose.This is common table sugar and it comes from sugar cane and sugar beets. Maple syrup also contains sucrose. Maltose is derived from the coupling of two molecules of glucose.It is produced when the enzyme amylase breaks down starch. Maltose is formed in germinating cereal grains and is important in the production of alcohol by fermentation. This is a disaccharide of galactose and glucose.Lactose is also called milk sugar and it makes up between 2 and 8 % of milk. Most reactions involve the combination of an electrophile and a nucleophile. Remember that a strongly electrophilic carbon is formed by the protonation of a simple sugar. The cation on carbon is stabilized by the adjacent oxygen atom. The empty p orbital on carbon can overlap with the filled p orbital on oxygen. The carbon is still electron-poor though and will react rapidly with nucleophiles. Most reactions can be viewed as the addition of a nucleophile to an electrophile. In acid-base reactions, the base is also a nucleophile and combines with the proton, an electrophile. When carb Continue reading >>

Carbohydrates

Carbohydrates (also called saccharides) are molecular compounds made from just three elements: carbon, hydrogen and oxygen. Monosaccharides (e.g. glucose) and disaccharides (e.g. sucrose) are relatively small molecules. They are often called sugars. Other carbohydrate molecules are very large (polysaccharides such as starch and cellulose). Carbohydrates are: a source of energy for the body e.g. glucose and a store of energy, e.g. starch in plants building blocks for polysaccharides (giant carbohydrates), e.g. cellulose in plants and glycogen in the human body components of other molecules eg DNA, RNA, glycolipids, glycoproteins, ATP Monosaccharides Monosaccharides are the simplest carbohydrates and are often called single sugars. They are the building blocks from which all bigger carbohydrates are made. Monosaccharides have the general molecular formula (CH2O)n, where n can be 3, 5 or 6. They can be classified according to the number of carbon atoms in a molecule: n = 3 trioses, e.g. glyceraldehyde n = 5 pentoses, e.g. ribose and deoxyribose ('pent' indicates 5) n = 6 hexoses, e.g. fructose, glucose and galactose ('hex' indicates 6) There is more than one molecule with the molecular formula C5H10O5 and more than one with the molecular formula C6H12O6. Molecules that have the same molecular formula but different structural formulae are called structural isomers. Glyceraldehyde's molecular formula is C3H6O3. Its structural formula shows it contains an aldehyde group (-CHO) and two hydroxyl groups (-OH). The presence of an aldehyde group means that glyceraldehyde can also be classified as an aldose. It is a reducing sugar and gives a positive test with Benedict's reagent. CH2OHCH(OH)CHO is oxidised by Benedict's reagent to CH2OHCH(OH)COOH; the aldehyde group is oxidised to Continue reading >>

Fructose

Fructose, or fruit sugar, is a simple ketonic monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide, sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into blood during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847.[4][5] The name “fructose” was coined in 1857 by the English chemist, William Allen Miller.[6] Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars.[7] Fructose is found in honey, tree and vine fruits, flowers, berries, and most root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. Crystalline fructose is the monosaccharide, dried, ground, and of high purity. High-fructose corn syrup is a mixture of glucose and fructose as monosaccharides. Sucrose is a compound with one molecule of glucose covalently linked to one molecule of fructose. All forms of fructose, including fruits and juices, are commonly added to foods and drinks for palatability and taste enhancement, and for browning of some foods, such as baked goods. About 240,000 tonnes of crystalline fructose are produced annually.[8] As for any sugar, excessive consumption of fructose may contribute to insulin resistance, obesity,[9] elevated LDL cholesterol and triglycerides, leading to metabolic syndrome,[10][11][12] type 2 diabetes and cardiovascular disease.[13] The European Food Safety Authority stated that fructose is preferable over sucrose and glucose in sugar-sweetened foods and beverages because of its lower effect on postprandial blood sugar levels, and also noted that “high intakes of fructose may lead to metabolic complications such as dys Continue reading >>

What Is Produced When Fructose & Glucose Are Combined?

What Is Produced When Fructose & Glucose Are Combined? by Cassidy Velez; Updated October 26, 2017 Glucose and fructose, two monosaccharides, when added together form sucrose, a disaccharide. It comes from sugar cane or sugar beets, and it is commonly known as table sugar. The formation of sucrose occurs when the hydroxide (OH) ions of a glucose and fructose molecule react with each other. A byproduct of the formation of sucrose is water. When the hydroxide ions of glucose and fructose combine, they are bonded together by one of the oxygen molecules. What are left are two hydrogen ions and an oxygen molecule, which is water. For the body to use sucrose, it must be broken down into its monosaccharides by sucrase (the enzyme needed to metabolize sucrose). Sucrose, specifically table sugar, is found abundantly in sugar cane and sugar beets. It is also found in most fruits and vegetables. Individuals with intolerance to sucrose lack the sucrase enzyme, which is necessary to break down sucrose. These individuals also often lack the maltase enzyme, which is needed to breakdown another disaccharide known as maltose. Continue reading >>

Degradation Of Sucrose, Glucose And Fructose In Concentrated Aqueous Solutions Under Constant Ph Conditions At Elevated Temperature

Degradation of Sucrose, Glucose and Fructose in Concentrated Aqueous Solutions Under Constant pH Conditions at Elevated Temperature Degradation of Sucrose, Glucose and Fructose in Concentrated Aqueous Solutions Under Constant pH Conditions at Elevated Temperature Get access/doi/pdf/10.1080/07328300008544153?needAccess=true The degradation of sucrose can decrease sucrose yield, reduce the efficiency of sugar factory and refinery processes, and effect end product quality. Characterization of sucrose degradation under modeled industrial processing conditions will underpin further technological improvements. Effects of constant reaction pH on sucrose degradation were investigated using simulated industrial model systems (100 C; 65 Brix [% dissolved solids]; N2; 0.05-3 mol NaOH titrant; 8 h), with the use of an autotitrator. Reaction pH values ranged from 4.40 to 10.45. Polarimetry and ion chromatography with integrated pulsed amperometric detection (IC-IPAD) were used to quantify sucrose degradation and first-order reaction constants were calculated. Minimum sucrose degradation occurred between pH 6.45 - 8.50, with minimum color formation between pH's 4.40 - 7.00. Polarimetry, often used in U.S. sugar factories and refineries to monitor chemical sucrose losses, was shown not to be viable to measure sucrose degradation under alkaline conditions, because of the formation of fructose degradation products with an overall positive optical rotation. For comparison, fructose and glucose (80 C; 65 Brix; N2; 3 mol NaOH; 2 h) were also degraded at constant pH 8.3 conditions. For sucrose, fructose, and glucose, formation of organic acids on degradation was concomitant with color formation, indicating they are probably produced from similar reaction pathways. For the glucose and fruct Continue reading >>

The Chemistry Of Honey

Flasks and beakers filled with bio fuels, shot on textured metal lab table with space for copy Honey bees are chemists. Using enzymes and dehydration, these scientists of the natural world are able to change the sugar in nectar into a supersaturated power food. Its no small feat-honey is composed of at least 181 components. Its unique taste is a result of complex chemical processes, which is why sugary syrup substitutes just cant compare. They cant mimic Mother Natures chemical know-how. Last year alone, bees in the United States produced a whopping 158 million pounds of honey. Thats a lot of chemistry. Honey is composed mostly of the sugars glucose and fructose. Its what scientists term a supersaturated solution. When sugar is stirred into a glass of water, some sugar is usually left at the bottom. Thats because the water (solvent) will only dissolve a certain amount. But, if the water is heated, more sugar can be dissolved. Consequently, in supersaturation, heat, enzymes or other chemical agents can increase the amount of material dissolved. These solutions tend to crystallize easily. Syrup, fudge and honey are all considered to be supersaturated solutions. Because of its supersaturation and low water content (15-18%), honey is viscous. That means it is rather thick in consistency and sometimes its solid. Its main ingredients are carbohydrates (sugars,) but it also contains, vitamins, minerals, amino acids, enzymes, organic acids, pollen, fragrance and flavor compounds. All honey begins with nectar. Whereas honey is viscous and has a low water content, nectar is about 80% water. Its a very thin solution- colorless and not nearly as sweet as honey. Its also chemically different. Through the use of enzymes, bees are able to convert the complex sugar in nectar into more Continue reading >>

Organic Chemistry - How To Convert Glucose To Fructose - Chemistry Stack Exchange

This conversion is done enzymatically on industrial scale using "glucose isomerase". ssavec Dec 16 '13 at 16:11 thank you! are there any other methods, more 'chemical' in nature? Shubham Dec 16 '13 at 17:06 Probably yes, but in general, all sugar chemistry is nasty, as the -OH groups are very similar and it is difficult to perform efficient synthesis. And impossible to do simple synthesis. ssavec Dec 17 '13 at 6:52 After searching on Google about Isomerization of Glucose to Fructose , you can find so many sources that explain the process. I think that this one is easy to understand among them. It explains that The isomerization of glucose to fructose is part of the glycolysis cycle that converts glucose to pyruvate. The way this is done is to isomerize the aldehyde (hemiacetal) glucose to the ketone (as a hemiacetal) fructose,and make another phosphate ester. The isomerization takes advantage of the ease of breakage of a C-H bond which involves a carbon next to a carbonyl carbon. This gives a clear Idea on the mechanism of Glucose Isomerage to fructose. :) Continue reading >>

Fructose- Structure, Properties & Uses Of Fructose | Chemistry | Byju's

Fructose is a simple ketonic monosaccharide. Monosaccharides are the fundamental units of carbohydrates which cannot be further reduced to simpler compounds. They are classified based on the functional group attached to the carbohydrate. Aldose is a carbohydrate which contains an aldehyde group and ketose contains a ketonic group. It is also called fruit sugar. Fructose along with glucose and galactose are three monosaccharides which are an important part of our diet. French chemist Augustin-Pierre Debrunfaut first discovered fruit sugar. It is found in trees, berries, honey, flowers, vine and tree fruits and most root vegetables. It is often bonded with sucrose to form a disaccharide. Commercially this sugar has been derived from corn, sugar cane, and sugar beets. But if taken in excess, it can cause obesity, insulin resistance just to name a few. Physical and Chemical Properties of Fructose: The carbohydrate can be fermented anaerobically with the help of yeast or bacteria in which they are converted into carbon dioxide and ethanol . Fruit sugar is used in Maillard Reaction with amino acids over glucose as the reaction occurs rapidly as they are present in an open chain form. These compounds dehydrate rapidly to give hydroxymethylfurfural(HMF). These carbohydrates are highly soluble when compared to other sugars. They absorb moisture quickly and release it slowly into the environment with respect to other sugars. Due to the presence of the keto group, it results in the formation of intramolecular hemiacetal. In this arrangement, C5-OH combines with the ketonic group present in the second position. This results in the formation of chiral carbon and two arrangements of CH2OH and OH group. Hence D-fructose exhibits stereoisomerism in which -D-fructopyranose and -D-fruct Continue reading >>

Sugar Inversion Making An Inverted Syrup

Sugar Inversion Making an Inverted Syrup Many people forget or dont realise that there are several types of sugar: Glucose or dextrose is by far the most important because it is what our body uses to produce energy but also lactose, sucrose, fructose, inverted sugar, etc. are all examples of sugars that are present in different types of food i.e. milk, fruit, granulated sugar, honey. Inverted Sugar is quite an interesting one and often found in many recipes here at Giapo ice cream in New Zealand. It is unlike a syrup which is just made from dissolving sugar into water and heating it we use an inverted syrup. Sugars are made up of carbons, hydrogens and oxygen atoms the different types of sugars are based on the different configurations of these atoms. Inversion in chemistry is the rearrangement of atoms to create different molecular configurations. An inverted syrup can be made by boiling equal parts of water and granulated sugar with a pinch of cream of tartar (acid catalyst) or lemon juice which results in an inverted syrup made up of equal parts of glucose and fructose. Another example of this is when yeast cells are mixed in a dough (or beer), they begin their digestion process by releasing an activated enzyme called invertase. This breaks down sucrose into simpler components glucose and fructose. This reaction is called hydrolysis (breaking of bonds and addition of water) and is used to split up a complex molecule into its simple constituents. Invert syrups are favourable in food processes in these ways: hygroscopic properties: absorbs moisture from the atmosphere so longer shelf life. sweeter than sucrose syrups: use less for the same amount of sweetness because 50% is fructose. easier to dissolve: preferable in cooking. As mentioned before, there are two ways in Continue reading >>

Fructose | Chemical Compound | Britannica.com

Fructose, a member of a group of carbohydrates known as simple sugars, or monosaccharides. Fructose, along with glucose , occurs in fruits, honey , and syrups; it also occurs in certain vegetables. It is a component, along with glucose, of the disaccharide sucrose , or common table sugar. Phosphate derivatives of fructose (e.g., fructose-1-phosphate, fructose-1,6-diphosphate) are important in the metabolism of carbohydrates. sugar; corn syrupExplaining the chemical differences between high-fructose corn syrup and sugar. 4 references found in Britannica articles Corrections? Updates? Help us improve this article! Contact our editors with your feedback. Error when sending the email. Try again later. We welcome suggested improvements to any of our articles. You can make it easier for us to review and, hopefully, publish your contribution by keeping a few points in mind. Encyclopdia Britannica articles are written in a neutral objective tone for a general audience. You may find it helpful to search within the site to see how similar or related subjects are covered. Any text you add should be original, not copied from other sources. At the bottom of the article, feel free to list any sources that support your changes, so that we can fully understand their context. (Internet URLs are the best.) Your contribution may be further edited by our staff, and its publication is subject to our final approval. Unfortunately, our editorial approach may not be able to accommodate all contributions. Our editors will review what you've submitted, and if it meets our criteria, we'll add it to the article. Please note that our editors may make some formatting changes or correct spelling or grammatical errors, and may also contact you if any clarifications are needed. There was a problem wit Continue reading >>

Simple Sugars: Fructose, Glucose And Sucrose

Simple sugars are carbohydrates. Glucose and fructose are monosaccharides and sucrose is a disaccharide of the two combined with a bond. Glucose and fructose have the same molecular formula (C6H12O6) but glucose has a six member ring and fructose has a five member ring structure. Fructose is known as the fruit sugar as its make source in the diet is fruits and vegetables. Honey is also a good source. Glucose is known as grape sugar, blood sugar or corn sugar as these are its riches sources. Listed in food ingredients as dextrose. Sucrose is the sugar we know as sugar or table sugar. Typically extracted as cane or beet sugar. If sucrose is treated with acid or heat, it hydrolyzes to form glucose and fructose. This mixture of sucrose, glucose and fructose is also called invert sugar. Nutritionally, these sugars are the same as they all provide 4 Cal/g. This is true for starch and other digestible carbohydrates too. Of the three sugars, fructose is the sweetest and glucose the least sweet, so typically less fructose can be used than table sugar (sucrose) – if sucrose has a sweetness of one, fructose is 1.7 and glucose 0.74 Fructose is more soluble than other sugars and hard to crystallize because it is more hygroscopic and holds onto water stronger than the others. This means that fructose can be used to extend the shelf life of baked products more than other sugars. Wikipedia has lots information on sugars, including information on the three I am interested in fructose, glucose and sucrose. Continue reading >>

Difference Between Glucose And Fructose

Categorized under Science | Difference Between Glucose and Fructose While not everyone would classify themselves as sweet tooth, there are few people who would gladly give up all sugar from their diet. Sugar can take many forms but the most common are sucrose, glucose, and fructose. If one is searching for the lowest common denominator, there should then just be glucose and fructose because these two monosaccharides are the building blocks of sucrose. There are many similarities between glucose and fructose. They are both simple sugars, and are monosaccharides. Simple sugars contain only one type of carbohydrate as opposed to two like the disaccharide sucrose. The chemical formula for glucose and fructose are also the same: C6(H2O)6. Once they have entered the body, both sugars eventually make their way to the liver to be metabolized. Most processed and natural foods out there contain a combination of fructose and glucose. Even foods that you would expect to be nearly all fructose, such as high fructose corn syrup, actually have a 55%-45% composition in favor of fructose. There are a few key ways in which these two sugars differ though. While their chemical formula is the same, the molecules of glucose and fructose are laid out in different formations. They both start out by making a hexagon with their six carbon atoms. Each carbon is bound to a water molecule . Glucose is an aldohexose. Its carbon is attached to a hydrogen atom by a single bond and an oxygen atom by a double bond. Fructose is a ketohexose. Its carbon is attached only to an oxygen atom by a single bond. As aforementioned, both sugars end up in the liver. However, Glucose is eaten, absorbed into the blood stream, and makes it way to the liver where it is broken down to supply energy to the entire body. Continue reading >>