Carbohydrates Lab Report Essay

IntroductionCarbohydrates be essential in aliments as an energy start ( amylum is the main source of gracious calories), a flavouring ( naive excoriations argon usually sweet) and as a functional ing rubyient ( sucrose allows ice cream to be soft in the sp bezer xanthan gum thickens a low-fat salad dressing). Carbohydrates atomic number 18 a type of macronutrient make in m each foods and beverages. Most refined plunders atomic number 18 by nature occurring in plant-based foods, such as grains. Food manufacturers also add carbohydrates to bear upon foods in the get up of amylum or added sugar. As with all our approaches to food ing personnel casualtyients/constituents we entrust first examine the structure of carbohydrates and so try to tidy how their structures allow them to function as they do. As their name suggests, carbohydrates basically make up from sugar and pee, i.e. Cx(H2O)y, although this ratio is often not strictly true and occasionally former(a) atom s may be present. The carbons argon arranges in a chain ( nigh often 5-6 atoms) functionalized with alcohol roots. The terminal carbon from each champion carries either an aldehyde or a ketone functional group.Carbohydrates atomic number 18 classified based on size of base carbonchain, figure of speech of sugar social units, location of C=O and stereochemistry. Classifications of carbohydrate atomic number 18 monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharide is the slightest possible sugar unit. Examples entangle glucose, galactose or fruit sugar. When we talk slightly blood sugar we atomic number 18 referring to glucose in the blood glucose is a major source of energy for a cell. In human nutrition, galactose can be found most readily in milk and dairy products, while fructose is found mostly in vegetables and fruit. When monosaccharides merge together in linked groups they are known as polysaccharides. Disaccharide is dickens monos accharide pinchs stayed together. Polysaccharides are polymers. A simple compound is a monomer, while a manifold compound is a polymer which is made of two or more monomers. Disaccharides are polysaccharides poly specifies any(prenominal) number higher than one, while di specifies exactly two.Examples of disaccharides include lactose, maltose, and sucrose. If you bond one glucose touch with a fructose molecule you get a sucrose molecule. sucrose is found in table sugar, and is often pulped as a event of photosynthesis (sunlight absorbed by chlorophyll reacting with other compounds in plants). If you bond one glucose molecule with a galactose molecule you get lactose, which is ordinarily found in milk. amylum, animal stiffen, dextran and cellulose are polysaccharides. Polysaccharides differ not precisely if in the natural of their component monosaccharides but also in the length of their chain and in the substance of chain branching that occurs. Polysaccharides funct ion as shop materials, structural components, or protective substances.Thus, starch ( which exists in two forms amylose and amylopectin ), glycogen and other storage polysaccharides, as readily metabolizable food, provide energy reserves for cells. Chitin and cellulose provide strong support for the skeletons of arthropods and green plants, respectively. In this experiment those legal action that had been carried out means to determine the carbohydrate class of an unknown by carrying out a series of chemical answers with the unknown and known compounds in each class of carbohydrate such as the Molisch assay (general CHO), Barfoeds show (monosaccharides), Fehlings runnel ( bring down sugars), benedicts experiment ( cut down sugars) and unity scrutiny (amylose).ACTIVITY 3.1, MOLISCH campaign A GENERAL TEST FOR CARBOHYDRATES target areaTo render the carbohydrate ascendantMATERIALS1 % of carbohydrate solutions( lactose, glucose, starch, sucrose, cellulose, fructose, apple a nd surcharge ), distilled water(as control render), arduous sulphuric caustic, Molisch reagent. mechanismTest undergrounds, test render holder, get downper, 5ml pipet, churl rod, test underground rack, fume cupboardCAUTIONMolish reagent contains concentrated sulfuric acerb , which is toxic and corrosive. It can ca engagement severe burns. go along eye, skin clothing, and combustible material contact. Avoid ingesting the substance.If you spill any reagent or acid, immediately notify your laboratory instructor.NOTEDo not lay out your thumb over the open end of a test thermionic vacuum tube-shaped structure-shaped structure-shaped structure when mixing its contents. Your laboratory instructor will suggest vogues in which you can safely and thoroughly mix the contents of a test tube.PROCEDURES1. 2 ml of each of the 1% carbohydrate solutions that take up been active is added into one set of labelled test tubes. 2. 2 drops of Molisch reagent are added to each test tub e and is mixed well with a clean glass stirring rod. 3. The test tube is inclined. Then 3ml of concentrated sulphuric acid is added slowly and carefully sight the side of the tube to form a layer below the sugar solution.( This step is per make inside the fume cupboard ). 4. The answering solution did not been shook or mixed.5. The change of the solution is find and put down. ( A purple ring at the interface is indicative of a carbohydrate ). 6. The test solutions containing Molisch reagent is discarded into the container provided by laboratory instructor.RESULT watchwordCarbohydrates undergo dehydration reactions (loss of water) in the front line of concentrated sulfuric acid. Pentoses and hexoses form five subdivision oxygencontaining sound on dehydration. The five member ring, known as furfural, further reacts with Molisch reagent to form colouriseed compounds. Pentoses are then dehydrated to furfural, while hexoses are dehydrated to 5-hydroxymethylfurfural. Either of the se aldehydes, if present, will sign with two molecules of naphthol to form a purple-coloringed product. A lordly reaction is indicated by appearance of a purple ring at the interface surrounded by the acid and test layers.Monosaccharides extend a rapid lordly test. Glucose and fructose are monosaccharide. Disaccharides and polysaccharides react more slowly than monosaccharide. saccharose and lactose are disaccharide which also gave purple color ring. stiffen and cellulose gave slightly purple color because they are polysaccharides. Distilled water gave nix test because it is not carbohydrate. A overlarge apple has around 28-31 grams of carbohydrate. Apple and cabbage contain carbohydrate so that they gave purple ring in this test.CONCLUSIONGlucose, lactose, fructose, sucrose, starch and cellulose all are carbohydrates which send constructive test for Molisch test. A prove of distilled water is ready and tested as the controlling sample.ACTIVITY 3.2, BARFOEDS TESTA GENERA L TEST TO DISTINGUISH BETWEEN MONOSACCHARIDE AND DISACCHARIDESOBJECTIVETo delineate the given carbohydrate solutions as monosaccharides or disaccharides.MATERIALS1 % of carbohydrate solutions( lactose, glucose, starch, sucrose, cellulose, fructose), distilled water (as control tube), Barfoeds reagentAPPARATUSTest tubes, test tube holder, 5 ml pipette, pipette filler, stop watch, water bathtubCAUTION Barfoeds reagent is corrosive and an irritant. If you spill any of the solution on yourself or on the bench, immediately notify your laboratory instructor.PROCEDURES1. 5 ml of each of the carbohydrate solutions is added into one set of thelabelled test tubes. 2. 5 ml of Barfoeds reagent is added to each test.3. The contents of each tube are shook well. all the tubes are fixed in an actively boiling water bath at the uniform time. 4. After the water starts boiling again, the solutions is alter for 3.5 min. ( time is important since a false positive test can be obtained for monosacc harides with disaccharide, if the disaccharides are heated for more than 3.5 min thereby breaking down ( hydrolyzing ) to monosaccharides ). 5. During this stopover, the tubes are observed closely and any change of clarity of the solutions is noted. ( A positive test for monosaccharides is the appearance of a red effect of Cu?O in spite of appearance 1 or 2 minutes, if no fall down forms it indicates the presence of a disaccharide).RESULT1% CARBOHYDRATE SOLUTION governing body OF RED PRECIPITATEFructoseYesGlucoseYesCelluloseNoLactoseNosaccharoseNoStarchNoDistilled water(as control tube)No treatmentBarfoeds test distinguishes monosaccharides from disaccharides. Positive test for monosaccharides is the appearance of red precipitate (Cu2O) within 1-2 minutes. If no precipitate formed, indicates the presence of disaccharide. The red precipitate come from the reaction between thereduction of squealer (II) acetate to copper(I) oxide (Cu2O). RCHO + 2Cu2+ + 2H2O RCOOH + Cu2Ov + 4H+ T he aldehyde group of the monosaccharide which unremarkably forms a cyclic hemiacetal is oxidized to the carboxylate. Glucose and fructose which are monosaccharides show positive result in this test. Reducing disaccharides undergo the equal reaction, but do so at a slower rate. So, the timing to heat the sample is set to 3.5 minutes. However, the samples are heated no more than 3.5 minutes to keep on the disaccharide breaking down to monosaccharide. Lactose, sucrose, cellulose, starch and distilled water showed negative result in this test.CONCLUSION solo monosaccharide will give an immediate red precipitate in Barfoeds test that is glucose and fructose the other preserve solutions which are cellulose, lactose, sucrose, starch and distilled water do not show any changes.ACTIVITY 3.3 FEHLING TEST FOR REDUCINGOBJECTIVETo distinguish the diminution sugars and non- bring down sugarsMATERIALS1% of carbohydrate solutions ( glucose, fructose, cellulose, lactose, sucrose, starch ), di stilled water(as control tube), Fehling solution A ( 69.28 grams copper (II) convert pentahydrate turn in 1 litre of distilled water), Fehling solution B ( 346 grams Rochelle flavor ( potassium sodium tartrate tetrahydrate) and 120 grams sodium hydroxide in 1 litre of distilled water) APPARATUS5 ml pipette, test tubes, test tube holder, test tube rack, pipette filler, stop watchPROCEDURES1. 5 ml of carbohydrate solutions is added into one set of test tubes. 2. By development distinguishable glass pipettes, 5 ml of Fehling A and 5 ml of Fehling B are added into each test tubes. 3. The solution is heated in a boiling water bath for 5-10 minutes. 4. Red brick precipitate is formed for positive results.5. Changes in test tubes are recorded.RESULTSamplesResultLactosePositive-red brick precipitateGlucosePositive-red brick precipitateFructosePositive-red brick precipitateStarchNegative-no changesDistilled waterNegative-no changesCelluloseNegative-no changesSucroseNegative-no changesDI SCUSSIONFehlings solution is used to test for the presence of a reduce sugar. Fehlings solution was based on the aldehyde or ketone groups in the sugar structures. 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. the presence of aldehydes but not ketones is detected by reduction of the thick(p) voluptuous solution of copper(II) to a red precipitate of in dis alcohol-soluble copper oxide.Fructose, glucose and lactose show positive result in this test. All monosaccharides are reducing sugars. Many disaccharides, like lactose, also have a reducing form, as one of the two units may have an open-chain form with an aldehyde group. However, sucrose, in which the anomeric carbons of the two units are linked together, are non-reducing disaccharides since neither of the rings is capable of opening. Polysaccharides (sugars with multiple chemical rings) are non-reducing sugars. Polysaccharides haveclosed structures , which use free atoms to bond together their multiple rings, and take a often daylong time to be broken down. So, starch and cellulose which are polysaccharides have negative result in Fehlings test. Distilled water is not reducing sugar also shows negative result.CONCLUSIONFehling test is the common test which is used to determine the presence of reducing sugar. Fructose, lactose and glucose are reducing sugars which give brick red precipitate after the solutions are heated.ACTIVITY 3.4 benedictS TEST FOR REDUCINGOBJECTIVETo test for reducing sugarsMATERIALS1% of carbohydrate solutions ( glucose, fructose, cellulose, lactose, sucrose, starch ), 3M hydrochloric acid (HCl), benedicks reagent, distilled waterAPPARATUSTest tubes, test tube holder, test tube rack, 5 ml pipette, pipette filler, dropper, stop watch, water bathPROCEDURES1. 5 ml of Benedicts reagent and 2 ml of carbohydrate are added to a test tube and each tube is shook thoroughly. 2. All the tubes are placed in a boil ing water bath at the same time. The solutions are heated for 5-6 min. 3. all changes in color, in the transparencies and in the fundamental law and color of any precipitate are observed and recorded. 4. Later, 4 drops of 3M HCl are added to 5 ml of 1 % sucrose solution and is heated in the boiling water bath for 5 min. 5. 1 % starch solution is treated in the same way but the heating period was extended to 25-30 min. 6. 1-2 ml of each of solution is applied with Benedicts test in the same manner as before. 7. The results are comparabilityd with those obtained without acid treatment.RESULTSugar solutionResult of colour of the solutionStarch unused dispiritedLactoseBrick red precipitate are formedFructoseBrick red precipitate are formedSucroseLight fatCelluloseLight blue + white precipitateGlucoseBrick red precipitate are formedDistilled waterLight blueSucrose + HCIBrick red precipitate are formedStarch + HCILightDISCUSSIONThe Benedicts test is used to detect the presence of red ucing sugars (sugars with a free aldehyde or ketone group) such as glucose, fructose and lactose. All monosaccharides are reducing sugars they all have a free reactive carbonylicic group. Some disaccharides have exposed carbonyl groups and are also reducing sugars. Lactose which is disaccharides also called reducing sugar as it has the exposed carbonyl groups. Other disaccharides such as sucrose and starch are non-reducing sugars and will not react with Benedicts solution. Benedicts reagent is a mild oxidant with CuSO4, Cu (II) sulfate, as one of the reagents. In the presence of a reducing sugar, the blue solution of Cu (II) or Cu+2, is changed to a brick red/brown precipitate of Copper (I) or Cu+1 oxide,Cu2O. If there a small or large amount of the reducing sugar present, the color would range from green to brick red respectively. RCHO + 2Cu2+ + 4OH- RCOOH + Cu2O + 2H2O Sucrose indirectly produces a positive result with Benedicts reagent if heated with dilute hydrochloric acid pri or to the test, although after this treatment it is no long-term sucrose. The addition ofHCl hydrolysed the non-reducing sugar, as it split it up into its component monomers.The monomers are reducing sugars which gave the positive result on the second reducing sugar test. The virulent conditions and heat break the glycosidic bond in sucrose through hydrolysis. The products of sucrose decomposition are glucose and fructose, both of which can be detected by Benedicts reagent, as described above. This same goes for starch. But since starch has larger component compare to sucrose so it took a longer time to hydrolyse. That the purpose of heat it in longer time compare to sucrose. Without the addition of acid to sucrose solution, starch solution, the test given is negative. The solutions remain clear blue after the addition of Benedicts reagent and heating. water tap water is used only to show the example of negative result of Benedicts test. Thus it will not show any changes compare to the carbohydrates.CONCLUSIONBenedicts test is the common test which is used to determine the existence of reducing sugar. Fructose, lactose, and glucose are reducing sugars which give positive test. Starch and sucrose are non reducing sugars which give positive results after adding hydrochloric acid.ACTIVITY 3.6, IODINE TEST FOR POLYSACCHARIDESOBJECTIVETo test for polysaccharidesMATERIALS0.01M iodine, 0.12M KI , 1% carbohydrate solutions (cellulose and starch) , distilled waterAPPARATUSTest tubes, test tube rack , dropper.PROCEDURE1. Few drop of 0.01M iodine in 0.12M KI added to 1% starch and cellulose solutions. 2. Any changes to the colour are observed.RESULT1% CARBOHYDRATE SOLUTIONCOLOUR OBSERVEDStarchVivid blueCelluloseYellowish brownDISCUSSIONStarch gives positive result in Iodine test as the color of solution change from discolour to dark blue. The immediate formation of a vivid blue color indicates amylose. Vivid blue coloration forms due to the polyiodide complex formed . Cellulose is derived from D-glucose units, which condensed through beta(1-4)-glycosidic bond. This give cellulose to be a straight polymer therefore, it cant coil around iodine to produce blue colour as starch does. Only starch gives the color of vivid blue, this is because it contains amylase. The iodine molecules slip inside of the amylase coil. The amylose, or straight chain portion of starch, forms helices where iodine molecules assemble, forming a dark blue color.CONCLUSIONThe Iodine test is used to test for the presence of starch. Starch is a type of polysaccharide carbohydrate which is made up of amylose and amylopectin. It is one of the main sources of carbohydrate and present naturally in plant. Amylose in starch form dark blue complex with iodine.ACTIVITY 2.2 SOLUBILITY AND digestibleness TESTSOLUBILITY TESTOBJECTIVETo test the solubility in hot water and digestion by amylase.MATERIALS5g of starch, 5g of cellulose, distilled waterAPPARATUSTest tubes, test tube holder, g lass rod, test tube rack, fume cupboard, 2 extractor tubes, analytical balance, cylinder, graduated pipette, pipette filler, 2 evaporator dishes.PROCEDURE1 5 g of starch is measured and put into a cartridge remover tube2 40 ml of distilled of water is measured and poured into the same centrifugetube 3 Step 1 to 2 is repeated by replacing the starch with cellulose 4 Both of the tubes are heated the tube containing starch is heated for close 2-3 minutes whereas the tube containing cellulose is heated for about 10 minutes 5 After heating, both of the content of the tubes are allowed to placid down slightly 6 The tubes are put into a centrifuge with 3500 rpm for 10 minutes 7 Empty free weight for both of the evaporator dishes is measured 8 5 mL of the supported from both of the tubes is pipetted and poured into two separate evaporator dishes 9 The evaporator dishes are left in the oven long10 The weight of the evaporator dishes is measured again.11 The solubility results are rec orded and tabulated.RESULTSolubility (%) = Weight of wry out supernatant (g)Weight of the dried carbohydrates (g)For starch, solubility (%) = 0.0093g50.0023g= 0.01860 %For cellulose, solubility (%) = 0.0010g50.0027g= 0.002000 %CarbohydratesWeight of dry carbohydrates (gram)Weight of dried supernatant (gram)Solubility (%)Starch50.0023g24.8768g- 24.8675g= 0.0093g0.01860Cellulose50.0027g21.2150g- 21.2140g= 0.0010g0.002000DISCUSSIONIn this activity, the solubility is defined as the percentage ratio of the weight of dried supernatant to the weight of the dry starch. Solubility can be interpreted as the amount of the dissolved compound that is present in the test solution. From the calculations done, we can see that starch, with a percentage of solubility at 0.01860 %, whereas cellulose have 0.002000 %. Starch and cellulose are two very similar polymers. In fact, they are both made from the same monomer, glucose, and have the same glucose-based repeat units. Since the sugar molecules co ntain the hydroxyl radical radical group or OH, Thus it can form hydrogen bonds with water molecules, which makes it soluble in water, but only to a limited extent.However, the glucose units in starch are connected by alpha linkages while the glucose units in cellulose are connected by beta linkages. In starch, all the glucose repeat units are oriented in the same direction. But in cellulose, each succesive glucose unit is rotated 180 degrees around the axis of the polymer backbone chain, relative to the become repeat unit. Although cellulose contains hydroxyl groups too, but most of them are hydrogen-bonded to each other when the microfibrils stack together, which accounts for the strength of cellulose fibers. Theres less free hydroxyl groups that can hydrogen bond with water molecules, other than those hydroxyl groups thats present at the end of each cellulose chain, which causes the cellulose to be less soluble in water when compared to starch.CONCLUSIONAlthough both starch and cellulose are complex carbohydrates, which have large molecular weight size, significantly reducing their relation for water, but the hydroxyl groups that exist in the monomers itself actually guides to their insignificant solubility. However, the solubility will increase when these complex carbohydrates are broken down into its monomers where the hydroxyl groups can form hydrogen bonds with other water molecules easily due to the reduced molecular weight and size that affects the affinity for water.DIGESTIBILITY TESTOBJECTIVETo determine the digestibility of complex carbohydratesMATERIALSStarch powder, cellulose powder, enzyme amylase, benedicts solution, distilled waterAPPARATUS2 centrifuge tubes, measuring cylinder, analytical balance, pipette fillers, graduated pipettes, 2 droppers, 5 test tubes.PROCEDURE1 5 g of starch is measured and put into a centrifuge tube2 40 ml of distilled of water is measured and poured into the same centrifuge tube 3 Step 1 to 2 is repeated by repla cing the starch with cellulose 4 Both of the tubes are heated the tube containing starch is heated for about 2-3 minutes whereas the tube containing cellulose is heated for about 10 minutes 5 After heating, both of the tubes are allowed to cool down slightly 6 5 mL of starch is pipetted into a test tube7 Step 6 is repeated using a different test tube but a drop of amylase is dropped into it 8 5 mL of cellulose is pipetted into a test tube 9Step 8 is repeated using a different test tube but a drop of amylase is dropped into it 10 5 mL of distilled water is pipetted into the last test tube, and a drop of amylase is dropped into it 11 20 drops of benedicts solution is dropped into five of the test tubes 12 Any changes occurred is recorded and tabulated.ResultSamplesColours of the solutionsBenedict s test5 g of starchblueNegative5 g of starch with amylaseBrick red precipitate is formedPositive5 g of celluloseblueNegative5 g of cellulose with amylaseblueNegativeDistilled water with amyla se pitifulNegativeDISCUSSIONAmylase is one of the many members of a class of enzyme, hydrolases, that catalyse the hydrolysis of starch into smaller carbohydrate molecules such as maltose (a molecule composed of two glucose molecules). Two categories of amylases, denoted alpha and beta, differ in the way they attack the bonds of the starch molecules. Alpha-amylase is widespread among living organisms. In the digestive systems of military man and many other mammals, an alpha-amylase called ptyalin is produced by the salivary glands, whereas pancreatic amylase is secreted by the pancreas into the small intestine. In the experiment, the test tube that contains only distilled water served as a control for this experiment.As for the test tubes that contain starch and cellulose without the amylase, they give a negative result for Benedicts test, because for starch and cellulose, since both of them are complex carbohydrates, thus they have very few carbonyl groups which contribute to the compounds reducing properties. Starch is a non-reducing sugar which shows negative result in the Benedicts test. As for the test tube that contains starch and cellulose with the addition of a drop of enzyme, amylase, the test tube with starch gives a positive result, but not the test tube with cellulose. As we all know, enzyme amylase can only catalyzes the breakdown of starch into simpler sugars, but not cellulose. Cellulose only digested by cellulase enzyme. It is impossible for human digestive enzymes to break the glycosidic bond. Therefore, only the test tube containing starch treated with amylase gives a positive result for the Benedicts test.CONCLUSIONEnzyme is a highly specific throttle valve which can only converts a specific set of reactants into specific products. Amylase only hydrolyze the starch but not cellulose. From here, we can say that the human digestive system would not be able to digest the cellulose, because our digestive system only contains amylase, and not c ellulose. Therefore in the perspective of ahuman, we can conclude that the digestibility of starch is higher than cellulose, provided that the enzyme amylase is present.