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# How Do The Structures Of Glucose And Galactose Differ?

## Carbohydrates - Glucose

Galactose is more commonly found in the disaccharide, lactose or milk sugar. It is found as the monosaccharide in peas. Galactose is classified as a monosaccharide, an aldose, a hexose, and is a reducing sugar. Galactosemia - Genetic Enzyme Deficiency: One baby out of every 18,000 is born with a genetic defect of not being able to utilize galactose. Since galactose is in milk as part of lactose, it will build up in the blood and urine. Undiagnosed it may lead to mental retardation, failure to grow, formation of cataracts, and in sever cases death by liver damage. The disorder is caused by a deficiency in one or more enzymes required to metabolize galactose. The treatment for the disorder is to use a formula based upon the sugar sucrose rather than milk with lactose. The galactose free diet is critical only in infancy, since with maturation another enzyme is developed that can metabolize galactose. Continue reading >>

## Sugars: The Difference Between Fructose, Glucose And Sucrose

29/06/2016 7:43 AM AEST | Updated 15/07/2016 12:56 PM AEST Sugars: The Difference Between Fructose, Glucose And Sucrose We're not just confused, we're also misinformed. "Fructose is the worst for you." "No way, sucrose is the devil." "I don't eat any sugar." Sugar is confusing. While some people only use certain types of sugars, others dismiss them completely. But is this necessary, or even grounded? To help settle the confusion, we spoke to Alan Barclay -- accredited practising dietitian, spokesperson for the Dietitians Association of Australia and Chief Scientific Officer at the Glycemic Index Foundation . "All the sugars are used as a source of fuel, but there are subtle differences in the way they are digested and absorbed," Barclay said. "In foods in Australia, the most common sugars are monosaccharides (glucose, fructose and galactose), but mostly these are occurring as disaccharides (which are sucrose, lactose and maltose)." Monosaccharides and disaccharides are two kinds of simple sugars, which are a form of carbohydrate. Oligosaccharides and polysaccharides, on the other hand, contain more sugar combinations and are known as complex carbohydrates -- for example, whole grain breads, brown rice and sweet potatoes. Monosaccharides require the least effort by the body to break down, meaning they are available for energy more quickly than disaccharides. "Monosaccharides don't require any digestion and can be absorbed into the mouth," Barclay said. "The problem there is they can cause dental caries which is one of the primary reasons why we need to be careful of how much added sugar we're consuming." Glucose -- the body's main source of energy and is found in fruit such as pasta, whole grain bread, legumes and a range of vegetables. Fructose -- this 'fruit sugar' fo Continue reading >>

## What Is The Difference Between Glucose And Galactose?

What is the Difference Between Glucose and Galactose? Teo Quay is a health communication enthusiast based in Ottawa, Canada. She has been studying, teaching and working in the fields of exercise physiology and nutrition since 2007. Teo received a master's degree in human nutrition from the University of British Columbia. Glucose is found naturally in honey and other sweeteners.Photo Credit: rvbox/iStock/Getty Images Glucose and galactose are sugars made of a single sugar unit, also referred to as monosaccharides. They are found naturally in the food supply, or they result from the digestion of larger chains of sugar units in the human gastrointestinal tract. Glucose is the main sugar in the bloodstream and is also the form that our body stores in chains called glycogen. It is used to fuel daily activity and exercise. Glucose and galactose are both simple structures made of a six-carbon ring. They are almost identical, but galactose differs slightly in the orientation of functional groups around the fourth carbon. Galactose has a higher melting point than glucose as a result of the structural differences. The main difference between these two sugars from a sensory perspective is that glucose is substantially sweeter, though neither is as sweet as table sugar. Very few foods naturally contain glucose and galactose, with the exception of sweeteners like honey. However, longer chains of carbohydrates that contain glucose and galactose are very common in the food supply. The main sources of glucose are fruits and dried fruit such as raisins and apricots; fruit juices; and sweeteners like honey. The main source of galactose is foods containing lactose, such as dairy products, though it does occur naturally in honey and beets. Lactose is broken down to generate galactose and Continue reading >>

## Monosaccharides Glucose Fructose Galactose

Monosaccharides are the simplest carbohydrates and are classified according to whether they are aldehyde or ketone derivatives, as well as the number of atoms contained in the molecule. Single hexoses, glucose and galactose require no digestion and can be absorbed directly into the bloodstream. Hexoses contain six carbon atoms, and are found in foods, while pentoses, ribose and deoxyribose contain five carbon atoms and are produced during the metabolism of foodstuffs. Three common sugars—glucose, galactose, and fructose, share the same molecular formula: C6H12O6. Because of their six carbon atoms, each is a hexose. Although all three share the same molecular formula, the arrangement of atoms differs in each case. Substances such as these three, which have identical molecular formulas but different structural formulas, are known as structural isomers. "Blood sugar" is the immediate source of energy for cellular respiration. Glucose, which is also referred to as dextrose, is a moderately sweet sugar found in vegetables and fruit. When glucose is fermented by the enzyme zymase, in yeast, it results in the formation of carbon dioxide and ethyl alcohol. It is the basic structure to which all carbohydrates are reduced to in the end, for transport via the bloodstream and use by the cells of the body. Two different pathways are involved in the metabolism of glucose: one anaerobic and one aerobic. The anaerobic process occurs in the cytoplasm and is only moderately efficient. The aerobic cycle takes place in the mitochondria and results in the greatest release of energy. As the name implies, though, it requires oxygen. Galactose is not normally found in nature, but is mostly hydrolyzed from the disaccharide lactose, which is found in milk, as part of a disaccharide made by 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 >>

## Carbohydrates Flashcards | Quizlet

What is the empirical formula of monosaccharides? What is the term for sugars with a carbonyl group at the end of the carbon skeleton? What is the term for sugars with a carbonyl group within the carbon skeleton? What is the term for monosaccharides with three carbon? What is the molecular formula for triose monosaccharides? What are some examples of triose sugars? (Hint: produced during glycolysis) What is the term for monosaccharides with five carbon? What is the molecular formula for pentose monosaccharides? What are some examples of pentose sugars? ribose (component of RNA) and ribulose (intermediate in photosynthesis) What is the term for monosaccharides with six carbon? What is the molecular formula of hexose monosaccharides? Are glucose and galactose aldoses or ketoses? What are some of the functional groups present in carbohydrates? When do five or six carbon sugars such as glucose go into ring form? What is the most important function of carbohydrates? What is the name of the bond which holds two monosaccharides together? What is a glycosidic linkage and how is it formed? a covalent bond formed between two monosaccharides by a dehydration synthesis reaction Where is maltose found and what is it used for? found in grains and used in the production of beer molecules with the same chemical formula but with a different arrangement of atoms What are some examples of carbohydrate isomers? When in the dry state which form do five and six carbon sugars posses? How is alpha glucose different from beta glucose? In alpha glucose the hydroxyl group at carbon one is below the plane of the ring. In beta glucose the hydroxyl group at carbon one is above the plane of the ring. What is the structure of alpha glucose? (draw it) What is the structure of beta glucose? (draw it) W Continue reading >>

## Carbohydrates

Monosaccharides Carbohydrates are the most abundant biomolecule on Earth. Living organisms use carbohydrates as accessible energy to fuel cellular reactions and for structural support inside cell walls. Cells attach carbohydrate molecules to proteins and lipids, modifying structures to enhance functionality. For example, small carbohydrate molecules bonded to lipids in cell membranes improve cell identification, cell signaling, and complex immune system responses. The carbohydrate monomers deoxyribose and ribose are integral parts of DNA and RNA molecules. To recognize how carbohydrates function in living cells, we must understand their chemical structure. The structure of carbohydrates determines how energy is stored in carbohydrate bonds during photosynthesis and how breaking these bonds releases energy during cellular respiration. Biomolecules meet specific structural criteria to be classified as carbohydrates. Simple carbohydrates are modifications of short hydrocarbon chains. Several hydroxyls and one carbonyl functional group modify these hydrocarbon chains to create a monosaccharide, the base unit of all carbohydrates. Monosaccharides consist of a carbon chain of three or more carbon atoms containing a hydroxyl group attached to every carbon except one. The lone carbon atom is double-bonded to an oxygen atom, and this carbonyl group may be in any position along the carbon chain. Therefore, one oxygen atom and two hydrogen atoms are present for every carbon atom in a monosaccharide. Consequently, we can define monosaccharides as possessing the molecular formula (CH2O)n, where n equals the number of carbon atoms and must be greater than or equal to three. Monosaccharides (Greek, meaning “single sugar”) are simple sugars and are frequently named using the suffix Continue reading >>

## What's The Difference Between Alpha-glucose And Beta-glucose?

What's the difference between alpha-glucose and beta-glucose? beta D-glucose units makes up the structure of cellulose polysaccharides while alpha D-glucose units makes up the structure of polysaccharides starch. user9873 Nov 18 '14 at 14:12 $\alpha$-D-glucose and $\beta$-D-glucose are stereoisomers - they differ in the 3-dimensional configuration of atoms/groups at one or more positions. Note that the structures are almost identical, except that in the $\alpha$ form, the $\ce{OH}$ group on the far right is down, and, in the $\beta$ form, the $\ce{OH}$ group on the far right is up. More specifically, they are a class of stereoisomer called an anomer . Anomers are capable of interconverting in solution. All cyclic structures of monosaccharides exhibit anomeric $\alpha$ (down) and $\beta$ (up) versions. These differences occur at the anomeric acetal carbon (the only carbon with two $\ce{C-O}$ bonds. These two forms exist because all monosaccharides also have an open-chain form with one fewer stereocenter. When the chain closes to the cyclic structure, the aldehyde or ketone carbon becomes a stereocenter , and it can do so in either configuration. One configuration is preferred ($\beta$), but both exist. In the presence of acid or base (although water can fulfill this role if need be), the two anomers interconvert through the open form until dynamic equilibrium is established. The mechanism below starts with $\alpha$ in the upper left and finishes with $\beta$ in the lower right. The open-chain form is in the middle. Just to add, in the L-configuration, the situation is reversed, since you draw the CH2OH below the ring in the Haworth projection. In both cases, the structure is when the relevant groups are on the same side of the ring, and when they're on opposite sides. H Continue reading >>

## Difference Between Glucose And Galactose

Categorized under Nature , Science | Difference Between Glucose and Galactose Although the molecular formula of glucose and galactose are identical, they have distinct structural formulas. Glucose is a simple sugar (monosaccharide) and also termed as blood sugar, grape sugar or corn sugar. It is a vital carbohydrate in biology. It is a premium source of energy for the living cells and also acts as a metabolic intermediate. It is among the chief products extorted from the process of photosynthesis. On the other hand, galactose also comes under the family of monosaccharide and it is a type of sugar that is less sweet in comparison to glucose. It consists of food energy (expressed in calories or joules) and termed as nutritive sweetener. There are only two stereoisomers actually known as glucose in the category of aldohexose sugars. In these two stereoisomers, only dextrose monohydrate (commonly known as D-glucose) is organically active. In contrast, there is polymer of sugar galactose called galactan. It exists in the body to maintain the supply of galactose. It is stored inside the body in bulk form at a place called hemicellulose. Whenever there will be an additional requirement of galactose than the process of hydrolysis takes place and galactan is eventually converted into galactose. Coming back to glucose, besides D-glucose there is one more glucose, which is biologically inactive. The inactive form of glucose is termed as L-glucose. It is not possible to metabolize the molecules of L-glucose by the process called glycolysis. Glucose and galactose are also synthesized by the body. However, the external sources will vary from each other. Glucose can be divided into two types: simple carbohydrate and complex carbohydrate. Simple carbohydrates easily get to digest and Continue reading >>

## Difference Between Glucose And Galactose

Home / Science & Nature / Science / Chemistry / Difference Between Glucose and Galactose Glucose and galactose are categorized as carbohydrates. Carbohydrates are a group of compounds which are defined as polyhydroxy aldehydes and ketones or substances that hydrolyze to yield polyhydroxy aldehydes and ketones. Carbohydrates are the most abundant type of organic molecules on earth. They are the source of chemical energy for living organisms. Not only this, they serve as important constituents of tissues. Carbohydrate can be again categorized into three as monosaccharide, disaccharides and polysaccharides. Monosaccharides are the simplest carbohydrate type. Glucose and galactose are monosaccharides. Monosaccharides are classified according to, The number of carbon atoms present in the molecule Whether they contain an aldehyde or keto group Therefore, a monosaccharide with six carbon atoms is called a hexose. If there are five carbon atoms, then it is a pentose. Further, if the monosaccharide has an aldehyde group, it is called as aldose. A monosaccharide with a keto group is called a ketose. Glucose is a monosaccharide that contains six carbon atoms and an aldehyde group. Therefore, it is a hexose and an aldose. It has four hydroxyl groups and has the following structure. Though it is shown as a linear structure, glucose can be present as a cyclic structure too. In fact in a solution, majority of the molecules are in the cyclic structure. When a cyclic structure is forming, the -OH on carbon 5 is converted into the ether linkage to close the ring with carbon 1. This forms a six member ring structure. The ring is also called a hemiacetal ring, due to the presence of carbon that has both an ether oxygen and an alcohol group. Because of the free aldehyde group, glucose can Continue reading >>

## Difference Between Glucose And Galactose

Home Science Chemistry Biochemistry Difference Between Glucose and Galactose Carbohydrates are the major components of all living organisms. Glucose and galactose are carbohydrates. Monosaccharides are the building blocks of larger carbohydrate molecules. The main difference between Glucose and Galactose is the position of each hydroxyl group in the 4th carbon; the position of hydroxyl group (-OH) in the 4th carbon is horizontal in the chair confirmation of the Glucose whereas the position of hydroxyl group (-OH) in the 4th carbon is upward in the chair confirmation of the Galactose. Key Terms: Aldohexose, Carbohydrates, D-Glucose, Galactose, Glucose, Hexose, Molecular Formula, Monosaccharides Glucose is a simple sugar. It is a monosaccharide. The molecular formula of Glucose is C6H12O6. Its chemical structure has four OH groups along with a -CH2OH group. Since it has six OH groups, glucose is called a Hexose. In the Fischer projection, glucose has a terminal aldehyde group. Therefore, glucose is called an aldohexose. Figure 1: The chair confirmation of D-Glucose The above image shows the general structure of glucose. This image indicates that glucose has four chiral centers . (A chiral center is a carbon atom having four different groups attached to it.) Therefore, glucose has stereoisomers. The naturally occurring glucose is known as D-Glucose. The isomer of D-Glucose is L-Glucose. But the L-Glucose does not occur naturally. Glucose is water soluble and is colorless when dissolved in water. Glucose can occur as an open chain or as a cyclic structure. But the open chain is typically unstable and spontaneously converts into cyclic form. The melting point of glucose is about 1460C (for alpha-D-Glucose). Aqueous solutions of glucose are able to rotate plane polarized lig Continue reading >>

## Difference Between Glucose And Galactose

Key Difference: The term glucose is derived from the Greek, glukus, meaning sweet. Glucose is also known as D-glucose, dextrose, or grape sugar is found in plants and it is a byproduct of photosynthesis and fuels for cellular respiration. Glucose is used as energy by living organisms. Galactose is a monosaccharide sugar that is less sweet compared to glucose. It is a C-4 epimer of glucose. Sugars are categorized as carbohydrates, which are a group of compounds made up of carbon, hydrogen and oxygen. Carbohydrates, and in turn sugars, are the source of chemical energy for living organisms, including humans. Sugars are categorized as monosaccharide, disaccharides and polysaccharides. Monosaccharides are the simplest carbohydrate type, composed of a single molecule. These include glucose, galactose, and fructose. Disaccharides are made up of two molecules. The table sugar, also known as sucrose, most commonly used by humans, is a type of disaccharide. Other disaccharides include maltose and lactose. The term glucose is derived from the Greek, glukus, meaning sweet. The suffix -ose denotes that it is a sugar. Glucose is also known as D-glucose, dextrose, or grape sugar is found in plants and it is a byproduct of photosynthesis and fuels for cellular respiration. Photosynthesis is the process where the plants produce their own food using carbon dioxide, water and sunlight. It is a dietary carbohydrate that is directly absorbed in the bloodstream during digestion. In living organisms such as humans, plants and animals, glucose is used as body fuel and energy. Excess glucose is stored in the form of glycogen in animals and humans and in the form of starch in plants. Glucose is an important part an organisms diet, which is used by an organism for growth and development. Use of Continue reading >>