is glycogen a reducing sugar is glycogen a reducing sugar

Thus, aldoses are reducing sugars. You can also make your own electrolyte replacement drink by adding a pinch of Celtic sea salt to some water with lemon. O-glycosidic linkages in cellulose are exclusively (1 4). If you want to deplete all of the glycogen stored in the liver and switch to burning fat instead, you may need to overhaul your diet. Polysaccharides - composed of a large number of polysaccharides. Difference Between Amylose and Amylopectin. Glycogen is as an important energy reservoir; when energy is required by the body, glycogen in broken down to glucose, which then enters the glycolytic or pentose phosphate pathway or is released into the bloodstream. BiologyOnline.com. Also, their major role is to act as the storage of energy in living bodies. When you move, especially during exercise, your body requires a fuel source, or energy, to operate. D-gluconate is not a reducing sugar because its anomeric carbon at C-1 is already oxidized to the level of a carboxylic acid . 4). Medications . Burning fat vs. glycogen can promote weight loss, increase your energy levels, balance your blood sugar and improve your concentration. By restricting carbohydrates and eating fat instead. All monosaccharides above are reducing sugars, and all polysaccharides are non-reducing. The monosaccharides are categorized into two groups: (1) aldoses that contain the free aldehyde group and (2) ketoses where there is a ketone group. The aldehyde can be oxidized via a redox reaction in which another compound is reduced. (c) Explain why fructose is also considered a reducing sugar. . Glucose is sourced by breaking down disaccharides or polysaccharides, which are larger sugar molecules. Exercise lowers blood sugar levels in normal patients and is easily recovered with foods. It should be remembered here that before acting as the reducing agents, ketoses must tautomerize aldoses. Reducing sugars are those which can act as reducing agents due to the presence of a free aldehyde or ketone group in them. Any carbohydrate that is capable of causing the reduction of some other substances without being hydrolyzed first is the reducing sugar whereas sugars that do not possess a free ketone or an aldehyde group are called the non-reducing sugar. Answer: Branches occur at every twelve to thirty residues along a chain of (14) linked glucoses. Amylopectin. The explanation for the incorrect option. If you consistently overeat, or you eat a lot of sugar and carbohydrates, this can actually cause weight gain over time. What is reducing sugar and nonreducing sugar? [3], 3,5-dinitrosalicylic acid is another test reagent, one that allows quantitative detection. Here we will discuss the dinitrosalicalic acid (DNSA) method to determine the reducing sugar content of a sample. In fact, you may even feel worse before you feel better. . Fehlings solution is made by mixing equal amounts of aqueous solutions of copper II sulfate pentahydrate and potassium sodium tartrate tetrahydrate. A reducing sugar. (Hint: It must first undergo a chemical conversion.) c. all of the -OH groups are equatorial. Is glycogen reducing or non reducing sugar? 2001-2023 BiologyOnline. These tests can be used in the laboratory for the determination of reducing sugar present in the urine which can be used to diagnose diabetes mellitus. Sucrose, starch, inositol gives a negative result, whereas lactose and maltose give a positive result with benedict's test. The branching enzyme can act upon only a branch having at least 11residues, and the enzyme may transfer to the same glucose chain or adjacent glucose chains. Muscle cell glycogen appears to function as an immediate reserve source of available glucose for muscle cells. . Like tollens reagent, an oxidizing agent is basic in nature therefore, the ketonic group gets isomerized to the aldehyde group and then can be oxidized to the acid group. For example : glucose, fructose, robose and xylose. Carbohydrates, especially reducing sugar are the most abundant organic molecules that can be found in nature. The disaccharides described above that are linked through a 1,4 linkage are called reducing sugars since they can act as reducing agents in reactions in which they get oxidized. All monosaccharides such as glucose are reducing sugars. "Sugars in which aldehyde or ketone functional groups are free are called reducing sugars, for example, lactose, maltose, and fructose.". Glycogen is synthesized from monomers of UDP-glucose initially by the protein glycogenin, which has two tyrosine anchors for the reducing end of glycogen, since glycogenin is a homodimer. . As cells absorb blood sugar, levels in the . These sugars are the carbohydrates that we often consume in our diet. 3), Two very important tests are often performed to identify the presence of reducing sugar. Chemical Properties Reducing Sugar:Reducing sugars have free aldehyde or ketone groups. Any information here should not be considered absolutely correct, complete, and up-to-date. Definition: a sugar that serves as a reducing agent. [11] However, evidence from epidemiological studies suggest that dietary acrylamide is unlikely to raise the risk of people developing cancer. The reducing sugars can be oxidized with some relatively mild oxidizing agents such as salts of metals. In the previous video you say that reducing sugars are sugars that are capable of . Therefore, you can conclude that a non-reducing sugar is present in . translocation from nucleus to cytoplasm of the liver which enhances glucokinase activity and subsequent synthesis of glycogen . When your body doesn't immediately need glucose from the food you eat for energy, it stores glucose . 7 Overnight oats make an easy and quick breakfast. Reducing sugar are the carbohydrates with free aldehyde and the ketone group while in the non-reducing sugar no such free groups are found; rather, they are available in the formation of bonds. Galactose is another example of reducing sugar. Choose whole, high-protein foods whenever possible. Carbohydrate is the body's preferred substrate during endurance exercise due to its more efficient energy yield . Lactose is composed of a molecule of galactose joined to a molecule of glucose by a -1,4 . Energy for glycogen synthesis comes from uridine triphosphate (UTP), which reacts with glucose-1-phosphate, forming UDP-glucose, in a reaction catalysed by UTPglucose-1-phosphate uridylyltransferase. Cellulose, starch, glycogen, and chitin are all polysaccharides examples. In medicines, the Fehling solution has been used as a test to detect diabetes in human blood. Verified. Not only did the low-carb group experience a significantly greater decrease in body mass, but they also demonstrated improved body composition, athletic performance and fat oxidation during exercise as well. Whereas those with diabetes and an insulin resistance cannot gain back the same energy from food due to the glucose not being able to be broken down properly into energy. [7] The reducing sugar reduces the copper(II) ions in these test solutions to copper(I), which then forms a brick red copper(I) oxide precipitate. Some of the disaccharides, oligosaccharides, polysaccharides, and all monosaccharides are reducing sugars. The reducing sugars are mainly monosaccharides where all polysaccharides are non-reducing sugars. The tollens reagent is an alkaline solution of ammoniacal silver nitrate. It is formed most often by the partial hydrolysis of starch and glycogen. The very important question that needs to be addressed here is this: why sucrose is the non-reducing sugar? In sucrose, there are glycosidic bonds between their anomeric carbons to retain the cyclic form of sucrose, avoiding its conversion into the form of an open chain with an aldehyde group. Glycogen is a highly branched polymer of glucose that serves as the main form of carbohydrate storage in animals. Restoration of normal glucose metabolism usually normalizes glycogen metabolism, as well. It is a component of lactose available in many dairy products. What are Non-reducing sugars? Afrikaans; ; Asturianu; Azrbaycanca; ; ; ; ; Bosanski; Catal; etina; Dansk Glycogen is the reserve polysaccharide in the body and is mainly comprised of hepatic glycogen. Reducing sugars are small carbohydrates (usually containing one or two sugar units) that are capable of acting as reducing agents towards metal salts such as Ag + or Cu 2+ . starch and glycogen). What is the structural formula of ethyl p Nitrobenzoate? Some of the disaccharides, oligosaccharides, polysaccharides, and all monosaccharides . G6P can be 1) broken down in glycolysis, 2) converted to glucose by gluconeogenesis, and 3) oxidized in the pentose phosphate pathway. The non-reducing end of the glycogen chain is the one having terminal sugar with no free functional group. In an alkaline solutions a reducing sugar forms so . If that specific hydroxyl is not attached to any other structure, that sugar is a reducing sugar. On average, each chain has length 12, tightly constrained to be between 11 and 15. This test is specifically used for the identification of monosaccharides, especially ketoses and aldoses. Glycogen Synthesis. Firstly, they are coupled, which means that in any oxidation reaction, there is a sideway reduction reaction. In food chemistry, the levels of reducing sugar in the products such as wine, juices, and sugar cane decide their quality. Reducing sugars reduce the Cu 2+ in Benedict's solution to Cu + which then forms a red precipitate, copper (I) oxide. ATP is the energy source that is typically used by an organism in its daily activities. The single reducing end has the C1 carbon of the glucose residue free from the ring and able to react. ii. Some of the most significant characteristics of reducing sugar have been summarized in the points below. Researchers took 20 male endurance-trained athletes and split them into two groups: high carbohydrates and low carbohydrates. The cyclic hemiacetal forms of aldoses can open to reveal an aldehyde, and certain ketoses can undergo tautomerization to become aldoses. Reducing substances comprise all the sugars exhibiting ketonic and aldehydic functions and are determined by their reducing action on an alkaline solution of a copper salt. Fructose and metabolic health: governed by hepatic glycogen status . Fehling's solution is a deep blue-coloured solution. Cellulose and glycogen: Both of these compounds are homopolysaccharides of D-glucose. . Examples: Maltose, lactose. The anomeric carbon of terminal sugar is linked to another glucose via glycosidic bond. Glycogen is broken down at these nonreducing ends by the enzyme glycogen phosphorylase to release glucose for energy. The empirical formula for glycogen of (C6H10O5)n was established by Kekul in 1858. Three very important polysaccharides are starch, glycogen and cellulose. You can drink plain water or water flavored with a little fresh lemon. The most common examples of reducing sugar are maltose, lactose, gentiobiose, cellobiose, and melibiose while sucrose and trehalose are placed in the examples of non-reducing sugars. Blood glucose from the portal vein enters liver cells (hepatocytes). The sugar structure with a free aldehyde or the ketone group is called the reducing end of sugar. In the Fehling test, the solution is warmed until the sample where the availability of reducing sugar has to be tested is homogeneously mixed in water after which the Fehling solution is added. A special debranching enzyme is needed to remove the (16)branches in branched glycogen and reshape the chain into a linear polymer. The balance-point is 2. . [4] Glycogen stores in skeletal muscle serve as a form of energy storage for the muscle itself;[4] however, the breakdown of muscle glycogen impedes muscle glucose uptake from the blood, thereby increasing the amount of blood glucose available for use in other tissues. The relative measurement of the number of oxidizing agents reduced by the available glucose makes it easy to calculate the concentration of glucose present in the human blood or urine. These metal salts have historically been used for testing purposes because they oxidize aldehydes and give a clear color change after being reduced. After hydrolysis and neutralization of the acid, the product may be a reducing sugar that gives normal reactions with the test solutions. It comes from carbohydrates (a macronutrient) in certain foods and fluids you consume. [20][21], Like amylopectin, glucose units are linked together linearly by (14) glycosidic bonds from one glucose to the next. Glycogen has several nonreducing ends and one reducing end. Two of them use solutions of copper(II) ions: Benedict's reagent (Cu2+ in aqueous sodium citrate) and Fehling's solution (Cu2+ in aqueous sodium tartrate). Harvard Medical School: What Is Keto Flu. It should be remembered here that starch is a non-reducing sugar as it does not have any reducing group present. Burning Fat Vs. Glycogen. The DNS method is used for estimating the concentration of reducing sugars in a sample It was originally invented by G. Miller in 1959. I love to write and share science related Stuff Here on my Website. When you're not getting energy directly from food, your body turns to glycogen. When it is needed for energy, glycogen is broken down and converted again to glucose. The redox reactions involve the transfer of hydrogen, oxygen, or electrons where two very important characteristics are common in all three reactions. (2018). [28], Glycogen synthesis is, unlike its breakdown, endergonicit requires the input of energy. Proper hydration is vital all the time, but it's especially important when you're in a fat-burning state. The leading sources pdf icon [PDF-30.6MB] external icon of added sugars in the US diet are sugar-sweetened beverages and desserts and sweet snacks. With one anomeric carbon unable to convert to the open-chain form, only the free anomeric carbon is available to reduce another compound, and it is called the reducing end of the disaccharide. In hypoglycemia caused by excessive insulin, liver glycogen levels are high, but the high insulin levels prevent the glycogenolysis necessary to maintain normal blood sugar levels. The structural isomers of the chemical compounds that can instantly interconvert are tautomers and the process in chemistry is referred to as tautomerization. [22], Each glycogen is essentially a ball of glucose trees, with around 12 layers, centered on a glycogenin protein, with three kinds of glucose chains: A, B, and C. There is only one C-chain, attached to the glycogenin. Secondly, they always involve a net chemical change where new substituents are formed by the reaction of reactants. Fructose is sourced from sugar cane, sugar beets, and corn. Two drops of iodine are added. 4. [3] It is the main storage form of glucose in the human body. Study now. What is glycogen metabolism? A reducing sugar is a carbohydrate that is oxidized by a weak oxidizing agent (an oxidizing agent capable of oxidizing aldehydes but not alcohols, such as the Tollens reagent) in basic aqueous solution. If you continuously eat carbohydrates in any form, your body will prioritize them, and the cycle will continue. Lactose (G + Gal) AKA "milk sugar" B( 1 4) glycosidic linkage. Glycogen has several nonreducing ends and one reducing end. The percentage of reducing sugars present in these starch derivatives is called dextrose equivalent (DE). In an alkaline solution, . It must be noted here that the reduction of aldehydes results in the formation of primary alcohols while the reduction of ketones gives secondary alcohols. For instance, lactose is a combination of D-galactose and D-glucose. The carbohydrates are stored in animal body as glycogen. The rest should come from protein. Lack of sugar will lead to lack of energy and is damaging for the body and blood sugar. [5], Glucose is an osmotic molecule, and can have profound effects on osmotic pressure in high concentrations possibly leading to cell damage or death if stored in the cell without being modified. [2], Several qualitative tests are used to detect the presence of reducing sugars. 5-step action plan for reducing sugar intake. The monosaccharides can be divided into two groups: the aldoses, which have an aldehyde group, and the ketoses, which have a ketone group. Right end of a polysaccharide chain is called reducing end while left end is called non-reducing end. Examples of reducing sugars include monosaccharides like galactose, glucose, glyceraldehyde, fructose, ribose, and xylose, disaccharides like cellobiose, lactose, and maltose, and polymers like glycogen. However, a non-reducing sugar can be hydrolyzed using dilute hydrochloric acid. However, it is inaccurate, expensive, and sensitive to impurities.[13]. D. Determination of the sugar content in a food sample is important. . [4] Kelly, M. Test for Reducing Sugars. It is present in liver, muscles and brain. Glycogen is found in the form of granules in the cytosol/cytoplasm in many cell types, and plays an important role in the glucose cycle. In addition, sticking to high-protein, low-carb foods may help reduce sugar cravings. release of glucose-1- phosphate (G1P), rearranging the remaining glycogen (as necessary) to permit continued breakdown, and. The chemical formulation of sugar is Cn(H2O)n (e.g., C6H12O6for glucose), which is naturally found in all fruits, dairy products, vegetables, and whole grains. (Ref. If the color changes to blue it means that there is no reducing sugar present. The name is based on its structure as it consists of an adenosinemolecule and three inorganicphosphates. Which of the following is NOT a reducing sugar? Reducing Sugar. If each chain has 0 or 1 branch points, we obtain essentially a long chain, not a sphere, and it would occupy too big a volume with only a few terminal glucose units for degrading. They provide a significant fraction of daily used dietary calories in most of the living organisms living on the earth. [5] Reducing Sugar | Baking Ingredients | BAKERpedia. Reducing Sugar vs Starch Any sugar which is capable of acting as a reducing agent is known as a reducing sugar. [4][6] In skeletal muscle, glycogen is found in a low concentration (12% of the muscle mass): the skeletal muscle of an adult weighing 70kg stores roughly 400grams of glycogen. The end of the molecule containing the free anomeric carbon is called the reducing end, and the other end is called the nonreducing end. Glucose passes into the cell and is used in Maltose is a reducing sugar. The two major energy sources are carbohydrates and fat, but if given the choice, your body will choose carbs. Common oxidising agents used to test for the presence of a reducing sugar are: Benedict's Solution (1) How does alkaline phosphatase affect P-nitrophenol? The most common example of ketose is fructose whereas glucose and galactose are aldoses. A rare sugar, D-psicose has progressively been evaluated as a unique metabolic regulator of glucose and lipid metabolism, and thus represents a promising compound for the treatment of type 2 diabetes mellitus (T2DM). conversion of G1P to G6P for further metabolism. Unlike table salt, Celtic sea salt contains trace minerals, like potassium, magnesium and calcium, that combine with the sodium to replenish electrolytes and prevent dehydration. The aldehyde functional group allows the sugar to act as a reducing agent, for example, in the Tollens' test or Benedict's test. If you rely on glycogen for energy, you'll eventually reach the point where you run out, unless you're consistently refeeding (or eating more carbohydrates to replenish your depleted glycogen stores). In order to switch from glycogen to fat burning, you have to prevent your body from getting access to glucose and glycogen. Incorporating a lot of high-intensity, aerobic workouts will help speed up the process too. It is essential for the proper functioning of brains and as a source of energy in various physical activities. Hence, option (C) is correct. Virtually every cell in the body can break down glucose for energy. The reducing sugar can reduce the capric ions of the Fehling or the Benedict solution into the cuprous ions whereas, the reduction of cupric ions into the cuprous ions is not achieved in the non-reducing sugars. A sugar that cannot donate electrons to other molecules and therefore cannot act as a reducing agent. Fehling's solution was used for many years as a diagnostic test for diabetes, a disease in which blood glucose levels are dangerously elevated by a failure to produce enough insulin (type 1 diabetes) or by an inability to respond to insulin (type 2 diabetes). It is very sensitive to even small quantities of reducing sugars (0.1%) and yields enough precipitate. In maltose, there are two glucose present. Key differences between reducing and non-reducing sugars: The reducing sugar is also mentioned as the compounds such as sugar or an element, for instance, calcium that lose an electron to another chemical or biological species in the reactions stated as the oxidation-reduction (often abbreviated as the redox reactions). [26][27], Glycogen was discovered by Claude Bernard. Other benefits of fat burning, or ketosis, include: Whether you call it the "keto diet," "low-carb high-fat (LCHF)" or "fat adaptation," the same principle applies. Also, the levels of reducing sugars in wine, juice, and sugarcane are indicative of the quality of these food products. The presence of sucrose can be tested in a sample using Benedict's test. 3 Answers. Another advantage of burning fat vs. glycogen is increased and sustained energy. When you're taking in more carbohydrates than the body can effectively store as glycogen (more calories in than out), it has no choice but to convert some and store it inside the fat cells. Amylopectin and -amylose are broken down by the enzyme amylase. Produced commercially from the juice of sugar cane and sugar beets. The non-reducing sugar form is in the acetal or the ketal form whereas the reducing forms are in the hemiketal or the hemiacetal. In another definition, any sugar that tends to act as the reducing agent since it has either an aldehyde group (-CHO) or the ketone group (-CO-) is called reducing sugar. A non-reducing sugar is a sugar that is NOT oxidised by mild oxidising agents. It is used to detect the presence of aldehydes and reducing sugars. When glycogen is broken down to be used as an energy source, glucose units are removed one at a time from the nonreducing ends by enzymes. reducing) group. . A nonreducing end of a sugar is one that contains an acetal group, whereas a reducing sugar end is either an aldehyde or a hemiacetal group (Fig. These tests are the Benedict test and the Fehling test. eg: sucrose, which contains neither a hemiacetal group nor a hemiketal group and, therefore, is stable in water. (Ref. 1). . [5] This includes common monosaccharides like galactose, glucose, glyceraldehyde, fructose, ribose, and xylose. Sciencing. Do humans have Cellobiase? Consuming less than 100 grams of carbs per day will begin to deplete glycogen stores. [4][5] In the liver, glycogen can make up 56% of the organ's fresh weight: the liver of an adult, weighing 1.5kg, can store roughly 100120grams of glycogen. Glycogenin remains bound to the reducing end of glycogen (the C1 hydroxyl . Benedict modified the Fehling's solution to make a single improved reagent, which is quite stable. Cellulose is a linear polymer, whereas glycogen is a branched polymer. But not all carbs are created equal! (a) Define "reducing sugar." (b) Show the reaction product of glucose after it is used as a reducing sugar. 1. The only significant exception is oyster, with glycogen chain length ranging 2-30, averaging 7. Different levels of resting muscle glycogen are reached by changing the number of glycogen particles, rather than increasing the size of existing particles[15] though most glycogen particles at rest are smaller than their theoretical maximum. Nonreducing disaccharides like sucrose and trehalose have glycosidic bonds between their anomeric carbons and thus cannot convert to an open-chain form with an aldehyde group; they are stuck in the cyclic form. Glycogen has several nonreducing ends and one reducing end. I think what you mean by the reducing end is the anomeric carbon. In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle. The second experiment is Benedict's test for reducing sugars. During its reaction with the reducing sugar, the blue copper sulfate in the solution is converted into red-brown copper sulfide. The unusual type of linkage between the two anomeric hydroxyl groups of glucose and fructose means that neither a free aldehyde group (on the glucose moiety) nor a free keto group (on the fructose moiety) is . Many disaccharides, like cellobiose, lactose, and maltose, also have a reducing form, as one of the two units may have an open-chain form with an aldehyde group. The main function of carbohydrates is to provide and store energy. All common monosaccharides are reducing sugars. Benedict's Test is used to test for simple carbohydrates. This test is . But if the color changes to green, yellow, orange, red, and then finally to dark red or brown color confirms the presence of reducing sugar in the food. Yes, glycogen has multiple free aldehydes which can reduce copper. Sugar metabolism 1) is the process by which energy contained in the foods that you eat is made available as fuel for your body. Glycogen is synthesized in the liver and muscles. Transcribed image text: 4. Oats are whole grains that have been shown to improve glycemic control and insulin sensitivity, which, in turn, help keep blood sugar levels low. Carbohydrate: a general term that applies to simple sugars to complex sugar polymers like glycogen, starch, and cellulose. Most of the methods for determination of carbohydrase activity are based on the analysis of reducing sugars (RSs) formed as a result of the enzymatic scission of the glycosidic bond between two carbohydrates or between a carbohydrate and a noncarbohydrate moiety. Potassium released from glycogen can Sugars are an essential structural component of living cells and a source of energy in many organisms. But burning fat vs. glycogen (the storage form of glucose from carbohydrates) can be more advantageous; you just have to train your body to get there. Reducing sugars react with amino acids in the Maillard reaction, a series of reactions that occurs while cooking food at high temperatures and that is important in determining the flavor of food. Non-reducing sugars-disacchrides in which the reducing group of monosaccharides are bonded, e.g. Yes, glycogen is made from glucose. [2], A sugar is classified as a reducing sugar only if it has an open-chain form with an aldehyde group or a free hemiacetal group. Some tissues, particularly the liver and skeletal muscle, store glucose in a form that can be rapidly mobilized, glycogen. From: nonreducing end in Oxford Dictionary of Biochemistry and Molecular Biology. No, glycogen lacks the free aldehyde necessary to reduce copper. The B-chains have on average 2 branch points, while the A-chains are terminal, thus unbranched. Glycogen is amylopectin with very short distances between the branching side-chains. (d) Sucrose is a disaccharide composed of glucose and fructose (Glc(1 2)Fru). You can also increase glycogen burning by strategically planning your workouts. Glucose is a reducing sugar because it belongs to the category of an aldose meaning its open-chain form contains an aldehyde group. Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. Exercising on an empty stomach can quickly deplete glycogen stores and force your body to turn to fat instead. If a reducing sugar is present, a colour change and precipitate will form (Aggarwal, 2001). [2] Gunawardena, G. (2016, January 4). Fat should provide around 70 to 80 percent of your calories. Examples are glucose, fructose, glyceraldehydes, lactose, arabinose and maltose, except for sucrose. The chemical configuration and structure of sugar particularly, glucose, fructose, and sucrose have been elaborated in Figure 1. This is important in understanding the reaction of sugars with Benedict's reagent. This phenomenon is referred to as "hitting the wall" in running and "bonking" in cycling. Each molecule of table sugar, or sucrose, is made up of a molecule of glucose and fructose.Glucose is used as fuel by most cell types and tissues in the body. In this postprandial or "fed" state, the liver takes in more glucose from the blood than it releases. Similarly, most polysaccharides have only one reducing end. It is a reducing sugar with only one reducing end, no matter how large the glycogen molecule is or how many branches it has (note, however, that the unique reducing end is usually covalently linked to glycogenin and will therefore not be reducing). After about eight glucose molecules have been added to a tyrosine residue, the enzyme glycogen synthase progressively lengthens the glycogen chain using UDP-glucose, adding (14)-bonded glucose to the nonreducing end of the glycogen chain.[29]. Branches are linked to the chains from which they are branching off by (16) glycosidic bonds between the first glucose of the new branch and a glucose on the stem chain. Another reducing sugar is fructose, which is the sweetest of all monosaccharides. The presence of glucose in the blood signals the pancreas to release the hormone insulin, which does one of two things with the glucose. . As a result, amylopectin has one reducing end and many nonreducing ends. B. Insulin acts on the hepatocytes to stimulate the action of several enzymes, including glycogen synthase.