Methodical Instruction for Students of the 1 Course Medical Faculty
LESSON № 3 (PRACTICAL – 6 HOURS)
Themes: 1. Chemical properties of monosaccharides.
2. Structure, composition and properties of disaccharides.
3. Structure, composition and properties of polysaccharides.
Aim: To study structure and properties of monosaccharides, disaccharides and polysaccharides. To determine monosaccharides, disaccharides and polysaccharides by qualitative tests.
Professional orientation of students:
Knowledge structure and properties of monosaccharides, oligosaccharides have beeecessary for understanding metabolism in a human organism. Natural carbohydrates: a glucose, fructose, starch are the main of monosaccharides in a human organisms. To be able qualitatively amout of monosaccharides in human body blood, and to explain they structure and properties are vary impotent for biological chemistry, pathological physiology and hygiene.
A lot of carbohydrates are oligosaccharides and human used thay. Olyhocaccharides have been structural components of biopolmers sach as polysaccharides, glycoproteins. They also serve as structural building blocks of cell and components of numerous metabolic intermediates.
Homopolysaccharide and heteropolysacchrides are impotent structural components of plant and animal organisms. Homopolysaccharides there are spare forms of carbohydrates in organisms (Example, the glycogen in an animal organism). Heteropolysaccharides have immune ptective effect element of cartilaginous tissue. Many polysaccharides can be blood substitutes (dextranes). The polysaccharides (starch, fat) are irreplaceable components food. The Celulose will be used in medical practice as bandage, gauze, cotton. Knowledge about structure and properties of polysaccharides have beeecessary for understanding processes, which are in an human organism and digestion of such subjects as biological chemistry, pharmacology, general hygiene.
Methodology of Practical Class (900-1200).
Investigation of structure, physical and chemical properties of mono- oligo- and polysaccharides.
Theme 1. Chemical properties of monosaccharides.
Work 1. To determine hydroxyl groups in glucose. Glucose is polyhydroxy-aldehyde, molecule which has five hydroxyl- and one aldehyde groups. The reaction between glucose and copper hydroxide has been used as a qualitative test for the hydroxyl groups, which are in molecule glucose.
Materials. 0,5 % solution of a glucose, 10 % solution of sodium hydroxide, 2 % solution of copper sulfates
Protocol. Add in the tube:
6 drops of 10 % sodium hydroxide solution;
1 drop of 2 % copper sulfates solution.
It is formed a pale blue, gelatinous solid of Copper (II) hydroxide.
To add in this test tube 1 drop of 0,5 % glucose solution;
The solution has been blue colour.
Work 2. Tromers’ reaction (Oxidation of glucose). Weak oxidizing agents, such as Tollens’, Fehling’s, and Benedict’s solutions, oxidize the end carbonyl group of а monosaccharide and prodused gyconic acid. Tromer’s solution react with glucose and reduces Cu2+ ion into Cu+ ion.
Materials. 0,5 % glucose solution, 10 % sodium hydroxide solution, 2 % copper sulfate solution.
Protocol. To add in test tube:
6 drops of 10 % sodium hydroxide solution.
1 drop of 2 % copper sulfate solution.
It is formed a pale blue, gelatinous solid of Copper (II) hydroxide.
To add tube 1-2 drops of 0,5 % Glucose solution in test tube and to heat mixture.
Reducing substances give а yellow precipitate of CuOH or а brick-red precipitate of Cu2O.
Work 3. To determine the glucose by Felings’ reagent (Oxidation of glucose). Glucose with Fehling’s solution reduces Cu2+ ion into Cu+ ion.
Materials. 0,5 % solution of a glucose, Felings’ reagent
Protocol. Add in the tube:
10 drops 0,5 % solution of a glucose
5 drops of Fehling’s reagent and heating test tube with mixture.
Reducing substances give а yellow precipitate of CuOH or а brick-red precipitate of Cu2O.
Work 4. To determine the glucose by Tolens’ reagent
Glucose with Tollens solution reduces Ag+ ion into Ag.
Materials. 0,5 % glucose solution, 10% NaOH solution, 10 % ammonia hydroxide (NH4OH) solution, 5 % silver nitrate (AgNO3) solution
Protocol. Add in the tube:
1 drop of 5 % AgNO3 solution,
1 drop of 10 % NaOH solution,
some drops of 10 % NH4OH solution, until brown color precipitate is dissolver.
After that 1-2 droups of 0,5 % solution of a glucose in other tube. To heat test tubes until boil. Silver will be form in the tube. You are writing this reaction.
Work 5. To determine a fructose by Selivanovs’ reagent.
Materials. 0,5 % fructose solution, concentrate hydrochloric acid, crystalline resorcin
Protocol. Add in the tube:
2 drops 0,5 % solution of a fructose
2 drops of solution of hydrochloric acid
some crystalline of resorcin and heating test tube until boil this mixture. Condensation substances red colour can form.
Theme 2. Structure, composition and properties of disaccharides.
Work 6. To determine hydroxyl groups in the sucrose molecule.
Sucrose molecule has eleven hydroxyl groups, because it are polyhydric compound. It can react with copper hydroxide and formed blue color complex, which can dissolve in water. This reaction has been used as qualitative test.
Materials. 1 % solution of a sucrose, 10 % sodium hydroxide solution, 2 % copper sulfate solution.
Protocol. Add in the tube:
1 drop 2 % copper sulfate solution.
6 drops 10 % sodium hydroxide solution.
It is formed a pale blue, gelatinous solid of Copper (II) hydroxide.
To add tube 1 drop 1 % sucrose solution. The solution has been bluer color.
Work 7. To hydrolyze sucrose. To determine products of sucrose hydrolysis.
Sucrose contain both a-glucose and b-fructose residues, sucrose differs from the previously described disaccharides in that the monosaccharides are linked through а glycosidic bond between both anomeric carbons. In acidic water solution it can hydrolyze to glucose and fructose, which determine by Tromer’s reaction and Selivanov’s reaction respectively.
Materials. 10 % a sucrose solution, 10 % a sodium hydroxide solution, 2 % a copper sulfate solution, concentrate hydrochloric acid, 2 mole/l hydrochloric acid, crystalline Resorcin.
Protocol. Add in the tube:
1 drop 10 % solution of the sucrose;
2 drops 2 mole/l hydrochloric acid;
6 drops water.
This mixture are heating until boil, sucrose has been hydrolyzed, and formed glucose, which determined by Tromer’s reaction (reaction (a)) and fructose, which determined by Selevanov’s reaction (reaction (b)).
Solution, which formed after hydrolyzation of sucrose, was separate to two tubes. In one of them to determined glucose (reaction (a)), and in second tube determine fructose (reaction (b)).
(a) Tromer’s reactoin (Oxidation of glucose).
Protocol. Add in the tube:
a few drops of a sucrose hydrolyzed
6 drops 10 % solution of sodium hydroxide
1 drop 2 % solution of copper sulfate and to heat mixture.
Reducing substances give а yellow precipitate of CuOH or а brick-red precipitate of Cu2O if gucose is present.
(b) To determine a fructose by Selivanov’s reagent.
Protocol. Add in the tube:
a few drops of a sucrose hydrolyzed
2 drops of concentrate hydrochloric acid solution;
some crystalline Resorcin and heating this mixture until boil.
if fructos is present in solution, so red color compound can form..
Work 8. To determine redusing property of lactose.
Lactose is composed of one molecule of galactose linked through the hydroxyl group on carbon 1 in a b-glucosidic linkage to the hydroxide of carbon 4 of molecule of glucose. Because the glucose component contains a hemiacetal group, lactose is a reducing sugar.
Materials. 1 % solution of a lactose, 10 % solution of sodium hydroxide, 2 % solution of copperr sulfates
Protocol. Add in the tube:
6 drops 10 % solution of sodium hydroxide
1 drop 2 % solution of copper sulphates
It is formed a pale blue, gelatinous solid of Copper (II) hydroxide.
To add tube 1-2 drops of 1 % Lactose solution in test tube and to heat mixture.
Reducing substances give а yellow precipitate of CuOH or а brick-red precipitate of Cu2O.
Theme 3. Structure, composition and properties of polysaccharides.
Work 9. The qualitative detection of starch.
The qualitative test for starch is iodine water solution. If added iodine solution to starch solution – blue color complex has been formed, because iodine molecules are adsorbed on molecules starch. This complex is broken, if this mixture is heated.
Materials. 0,5 % starch solution, iodine solution.
Protocol. Add in the test tube:
1 drop 0,5 % solution of the starch
1 drop solution of iodine
Blue color complex has been farmed. This mixture is warmed, the color of solution is change to white.
Work 10. The detection of no-reducing activity of starch.
Unlike monosaccharides and most disaccharides, polysaccharides do not test positive in Tollens, Benedict’s, and Fehling’s solutions, because it molecule has a few free aldegyde groups. In the presence of oxidizing agents, metal ions as Cu2+, and certain enzymes, starch and other polysaccharides are non readily undergo several oxidation reactions.
Materials. 0,5 % solution of a starch, 10 % solution of sodium hydroxide, 2 % solution of copper sulfate
Protocol. Add in the tube:
15 drops 0,5 % solution of a starch
6 drops 10 % solution of sodium hydroxide
1 drop 2 % solution of copper sulphate
This mixture are warmed
The yellow colour precipitate is not formed, because a few free aldehyde groups, which are in starch molecule can not determined by Tromer’s reagent.
Work 11. Acidic hydrolysis of starch.
Starch molecules are contain a-D-glycopyranose units, which attracted by a-D-1,4-glycoside linked or a-D-1,6-glycoside. If acidic hydrolysis is positive, you can detect D-glucose by Tromer’s reaction.
Materials. 0,5 % solution of a starch, solution of iodine, 10 % solution of sodium hydroxide, 2 % solution of copper sulfate, 2 mol/l solution sulfuric acid (H2SO4)
a) Acidic hydrolysis of starch:
Protocol. Add in the tube:
2 drops of 0,5 % starch solution
4 drops of 2 mol/l sulfuric acid (H2SO4) solution
Tube with solution put into the boiling water on 20 min.
Starch has been hydrolyzed by acid, and formed glucose, which determined by Tromer’s reaction (reaction (c)) and if acidic hydrolysis is negative, you can detect starch – blue color complex has been farmed (reaction (b)).
Because solution, which formed after hydrolyzation of starch, was separate to two tubes. In one of them to determined glucose (reaction (c)), and in second tube determine starch (reaction (b)).
b) Qualitative test by starch:
Protocol. Add in the tube:
a few drops of a starch hydrolyzed
1 drop solution of iodine
If acidic hydrolysis is negative, you can detect starch – blue color complex has been form.
c) Qualitative test by glucose (Tromer’s reaction)
Protocol. Add in the tube:
a few drops of a starch hydrolyzed
6 drops 10 % solution of sodium hydroxide
1 drop 2 % solution of copper sulfate and to heat mixture.
Reducing substances give а yellow precipitate of CuOH or а brick-red precipitate of Cu2O if gucose is present.
Work 12. Enzyme hydrolysis of starch.
Starch molecules are contain a-D-glycopyranose units, which attracted by a-D-1,4-glycoside linked or a-D-1,6-glycoside. If enzyme hydrolysis is positive, you can detect maltose by Tromer’s reaction.
Materials. 0,5 % solution of a starch, solution of iodine, 10 % solution of sodium hydroxide, 2 % solution of copper sulfate.
a) enzyme hydrolysis of starch
Protocol. Add in the tube:
2 drops of 0,5 % starch solution
Some drops of saliva.
Tube with solution put into the boiling water on 20 min.
Starch has been hydrolyzed by amylase, and formed maltose which determined by Tromer’s reaction (reaction (c)) and if enzyme hydrolysis is negative, you can detect starch – blue color complex has been farmed (reaction (b)).
Because solution, which formed after hydrolyzation of starch, was separate in to two tubes. In one of them to determined maltose (reaction (c)), and in second tube determine starch (reaction (b)).
b) qualitative detection of starch
Protocol. Add in the tube:
5 drop of solution after hydrolysis
1 drop solution of iodine
If acidic hydrolysis is negative, you can detect starch – blue color complex has been farmed.
c) qualitative detection of maltose:
Protocol. Add in the tube:
5 drop of solution after hydrolysis;
8 drops 10 % solution of sodium hydroxide;
1 drop 2 % solution of copper sulfate.
This mixture are boil.
If acidic hydrolysis is positive, you can detect D-maltose – the solution has been yellow-orange colour.
Individual Students Program.
1. Classification, structure, chemical properties of monosaccharides. (Secondary school course on chemistry).
2. Structure and properties of disaccharides, example the sucrose (Secondary school course on chemistry).
3. Structure of starch. (Secondary school course on chemistry).
I.Chemical properties of monosaccharides.
1. Carbohydrates.
2. Biological role of carbohydrates in an living organism.
3. Classification of carbohydrates.
4. Structure and stereoisomerism of monosaccharides.
5. Classification of monosaccharides.
6. Cyclic forms of monosaccharides.
7. Chemical properties of monosaccharides:
– mutarotation;
– oxidation: Tromer’s, Feling’s, Selivanove’s, Tollen’s reaction;
– reduction;
– glycoside formation;
– esters formation;
– amino sugar formation, they biological role;
8. Biologically important monosaccharides.
II. Structure, composition and properties of disaccharides.
1. Oligosaccharides.
2. Biological role of oligosaccharides.
3. Disaccharide. Reducing and non-reducing disaccharides.
4. Characteristic of structure and bonds of disaccharides.
5. Inverse sugar.
III. Structure, composition and properties of polysaccharides.
1. Polisaccharides. Classification of polysaccharides.
2. Structure homopolysaccharides, their properties and biological role in living organism.
3. Heteropolysaccharides, their structure and functions.
Seminar discussion of theoretical issues (1230– 1400 hour).
Test evaluation and situational tasks.
1. What functional group of glucose molecule can react with copper hydroxide (II)?
2. Yellow colour precipitate is formed, if Felings’ reagent has been added to solution. What compound are in solution?
3. Red colour compound are formed, if Selivanoves’ reagent has been added to solution. What compound are in solution?
4. In two tubes there is solution. If added to two tubes iodine, so in one of them blue color solution has been formed. But if to both tubes added copper hydroxide solution, so in second tube orange color precipitate has been formed. What kinds of compounds are in those tubes?
5. Formula of α-anomer is:
A. 
B.
C.
D.
E.
6.. What monossacharide is keto-hexose?
A.
B.
C.
D.
E.
7. In test tubers is: in first – glucose solution; in second – fructose; in third – starch.
A. Feling’s reagent;
B. Fole’s reagent;
C. Mohr’s reagent;
D. Adamcevich’s reagent;
E. Ninhydrin.
8. Glucose is heterofunctional compounds. What functional gpoups is in molecule glucos.
A. Carboxyl and keton.
B. Hydroxyl and carboxyl.
C. Aldehyde and hydroxyl.
D. Amino and keton.
E. Carboxyl and amino.
9. Aldohexose is all except:
A. D-glucose
B. D-galactose
C. D-mannose
D. D-fructose
E. D-idose
Correct answers of test evaluations and situational tasks:
1. Aldehyde group.
2. Glucose.
3. Fructose.
4. In first tube is starch, but in second tube are starch hydrolysis products.
5. C; 6. B; 7. A; 8. C; 9. D;
Individual student work (1415-1500 hour) are checked by solving situational tasks for each topic, answers in test evaluations and constructive questions (the instructor has tests & situational tasks).
Students must know:
– the biological role and chemical properties of monosaccharedes ;chamical properties of monosaccharides methods.
– the biological role and chemical properties of disaccharedes; chemical properties of disaccharides methods.
– the biological role ;
– structure of polysaccharides;
– chemical properties of polysaccharides ;
– methods of determination of monosaccharides.
Students should be able to:
– determine the monosaccharides in solution by qualitative test.
– determine the disaccharides in solution by qualitative test.
– determine the polysaccharides in solution by qualitative test.
References.
Basic:
1. Lecture notes.
2. http://intranet.tdmu.edu.ua/data/kafedra/internal/pharma_2/classes_stud/biological and bioorganic chemistry/medical/1 course/ lesson 03. Classification, structure and chemical properties of carbohydrates
3. http://intranet.tdmu.edu.ua/data/kafedra/internal/zag_him/presentations/biological and bioorganic chemistry/ Carbohydrates. Classification, structure and chemical properties of mono-, di-, oligo- and polysaccharides.
4. C. David Gutsche, Baniel J. Pasto. Fundamentals of Organic Chemistry. – New Jersey: Prentice -Hall, Inc.Englewood Cliffs, 2005. -1346 p.
5. Andrew Streltwieser, Jr. Clayton H. Hcathcocr. Introduction to Organic Chemistry. – New York: Macmillan Publishinc Co., 2006. – 1508 p.
6. Lewis D. E. Organic chemistry. A modern perspective. – Copyright, 2006. P. 512-601
Additional:
7. Andrew Streltwieser, Jr. Clayton H. Hcathcocr. Introduction to Organic Chemistry. – New York: Macmillan Publishinc Co., 2006. – 1508 p.
8. Lewis D. E. Organic chemistry. A modern perspective. – Copyright, 2006. P. 25 – 95
The methodical instruction has been worked out by: Associate Prof. Dmukhulska Ye. B.
Methodical instruction was discussed and adopted at the Department sitting
25.06.2013. Minutes N 11
Methodical instruction was adopted and reviewed at the Department sitting
27.08.2013. Minutes N 1
