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Sugars – sucrose

Powdered sugar
Source: domena publiczna.

Link to the lesson

Before you start you should know
  • what sugars are;

  • the division of sugars;

  • what properties simple sugars have.

You will learn
  • what the molecular formula for sucrose is;

  • to test and describe the properties and use of sucrose;

  • to write the equation for the reaction of sucrose with water.

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Nagranie dźwiękowe abstraktu 
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There are different types of sugars. Powdered sugar, vanillin sugar, white sugar, cane sugar.
Source: Tomorrow Sp.z o.o., licencja: CC BY 3.0.

Structure of sucrose

This sugar, which we use every day e.g. for sweetening tea, was already known in ancient times. It was obtained on an industrial scale from sugarcanes in the Middle East. It was brought to Europe by the Greeks in the 4th century BC. – at that time it was used as a medication. Deliveries to Europe increased significantly when America was discovered because sugarcane plantations were established there. In the mid‑18th century people started to obtain sugar from sugar beets. In Poland the first sugar factory was built in 1802 in Lower Silesia.

SucrosesucroseSucrose is one of the disaccharides and has the following formula: CIndeks dolny 12HIndeks dolny 22OIndeks dolny 11. The sucrose molecule is composed of fragments of two simple sugars: glucose and fructose.

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a) Structural formula of sucrose; b) Sucrose molecule model; c) Haworth formula of molecule
Source: Andrzej Bogusz, licencja: CC BY 3.0.

Are the properties of sucrose similar to those of glucose?

Task 1

Before conducting experiment, formulate research question and hypothesis.

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Analysis of the experiment: What are the properties of sucrose?. Research question (Uzupełnij). Hypothesis (Uzupełnij).
Test of sucrose properties
Experiment 1
Research problem

What are the properties of sucrose?

Hypothesis

Sucrose is a white, crystalline substance which dissolves well in water.

You will need
  • white sugar,

  • water,

  • test tube,

  • burner,

  • test tube holder.

Instruction
  1. Examine the properties of sugar: state of aggregation, colour and odour.

  2. Add a teaspoonful of sugar to water and evaluate the solubility of this substance in water.

  3. Add a teaspoonful of sugar into a test tube and heat it up.

  4. Observe the changes that occur.

Summary
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Observations (Uzupełnij). Conclusions (Uzupełnij).

The experiment provided the following information:

Substance

State of aggregation

Colour

Odour

Water solubility

Effect of heating

sugar

solid

white

odourless

dissolves well in water

sugar melts, changing colour to brown

Each of you can make candies called caramels. Just pour a few spoonfuls of sugar into a saucepan and keep it over low heat. As a result of heating, caramel is created, which should be poured into a bowl and allowed to cool down. Candy is ready!

Task 2

Before conducting experiment, formulate research question and hypothesis.

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Analysis of the experiment: Does sucrose (like glucose) give a positive result in the Trommer's test?. Research question (Uzupełnij). Hypothesis (Uzupełnij).
Trommer's test for sucrose
Experiment 2
Research problem

Does sucrose (like glucose) give a positive result in the Trommer's test?

Hypothesis

Sucrose do not gives a positive result in the Trommer's test.

You will need
  • test tube,

  • beaker,

  • burner,

  • tripod,

  • dropper,

  • aqueous solution of sucrose,

  • copper(II) sulfate solution,

  • sodium hydroxide solution,

  • water.

Instruction
  1. Place the aqueous sucrose solution in tube.

  2. Add a few cubic centimeters of the sodium hydroxide solution to a few cubic centimeters of the copper(II) sulfate solution, in order to precipitate copper(II) hydroxide.

  3. Add the freshly precipitated copper(II) hydroxide into the tube with the sucrose solution.

  4. Heat the resulting mixtures in the beaker with hot water.

  5. Observe the changes that occur.

Summary
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Observations (Uzupełnij). Conclusions (Uzupełnij).
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Film pokazuje eksperyment. Problem badawczy: Czy sacharoza wykazuje właściwości redukujące? Test Trommera dla sacharozy. Trommer's test for surcose. Hipoteza: Sacharoza jako dwucukier hydrolizuje na fruktozę i glukozę. Będziesz potrzebować: roztwór sacharozy, sucrose solution, roztwór siarczanu sześć miedzi dwa, copper (dwa) sulfate, roztwór wodorotlenku sodu, sodium hydroxide, szczypce do probówki, test tube clamps, zlewkę z wodą. Do próbówki pipetą wprowadzony został roztwór siarczanu sześć miedzi dwa, oraz wodorotlenku sodu. Opisano równanie reakcji: ce u es o cztery dodać dwa en a o ha strzałka w prawo ce u o ha dwa razy wzięte dodać en a dwa es o cztery. Wytrącony osad wodorotlenku miedzi dwa w środowisku zasadowych dodano do probówki zawierającej wodny roztwór sacharozy. Zaobserwowano dwie warstwy cieczy. Bezbarwną warstwę na dole i niebieską na górze cieczy. Następnie probówkę umieszczono w zlewce z wodą i ogrzano. Niebieski osad sczerniał. Opisano równania reakcji: ce u o ha dwa razy wzięte strzałka w prawo, nad strzałką napis temperatura, za strzałką ce u o dodać ha dwa o. Druga reakcja: ce dwanaście ha dwadzieścia dwa o jedenaście dodać dwa ce u o strzałka w prawo the reaction does not take place. Film wykazał, że sacharoza nie wykazuje właściwości redukujących.
Task 3

Before conducting experiment, formulate research question and hypothesis.

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Analysis of the experiment: Sucrose hydrolysis by hydrochloric acid. Research question (Uzupełnij). Hypothesis (Uzupełnij).
The hydrolysis of sucrose by hydrochloric acid
Experiment 3
Research problem

Does hydrochloric acid hydrolyze sucrose?

Hypothesis

Sucrose undergoes hydrolysis at acidic pH. Sucrose as a disaccharide hydrolyzes to D‑fructose and D‑glucose.

You will need
  • test tube,

  • dropper,

  • sodium hydroxide solution,

  • aqueous solution of sucrose,

  • hydrochloric acid,

  • all‑purpose indicator paper,

  • holder,

  • burner.

  1. Place the aqueous sucrose solution in tube.

  2. Pour a few drops of hydrochloric acid into the tube with the sucrose solution and heat it in the burner's flame. Then add the sodium hydroxide solution to neutralize the solution. Check the acidity of the solution using the all‑purpose indicator paper.

  3. Observe the changes that occur.

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Observations (Uzupełnij). Conclusions (Uzupełnij).
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Film pokazuje eksperyment hydrolizę sacharozy za pomocą kwasu solnego. Będziesz potrzebować: dwie probówki, zlewka, palnik, trójnóg, zakraplacz, wodny roztwór sacharozy, roztwór kwasu solnego, uniwersalny papierek wskaźnikowy, woda. Instrukcja: W dwóch probówkach umieść wodny roztwór sacharozy. Do jednej z probówek z roztworem sacharozy wlej kilka kropli kwasu solnego i ogrzej w płomieniu palnika. Następnie dodaj zasadę sodową, aby zobojętnić roztwór. Odczyn roztworu sprawdź za pomocą uniwersalnego papierka wskaźnikowego.

In the human body, during digestion, sucrose is broken down into simple sugars. The following are necessary for this reaction: enzymes, water and the hydrochloric acid found in the digestive tract. This process is called hydrolysis.
C12H22O11 + H2O enzymes, HCl C6H12O6 + C6H12O6sucrose + water  enzymes, HCl  glucose + fructose
The initial digestion of sucrose may begin already in the oral cavity under the influence of the enzyme – salivary amylase – present in the saliva. Therefore, sugar does not even need to be swallowed. Just put a small amount of it in your mouth and wait until saliva decomposes it into simple sugars. They will be absorbed by the epithelium of the oral cavity's mucous membrane.

Task 4

Before conducting experiment, formulate research question and hypothesis.

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Analysis of the experiment: Does hydrolysed sucrose give a positive result in the Trommer's test?. Research question (Uzupełnij). Hypothesis (Uzupełnij).
Trommer's test for hydrolysed sucrose
Experiment 4
Research problem

Does hydrolysed sucrose give a positive result in the Trommer's test?

Hypothesis

Sucrose as a disaccharide hydrolyzes to D‑fructose and D‑glucose. These monosaccharides give a positive result in the Trommer's test.

You will need
  • test tube,

  • beaker,

  • burner,

  • tripod,

  • dropper,

  • aqueous solution of hydrolysed sucrose,

  • copper(II) sulfate solution,

  • sodium hydroxide solution,

  • water.

Instruction
  1. Place the aqueous solution of hydrolyzed sucrose in the tube.

  2. Add a few cubic centimeters of the sodium hydroxide solution to a few cubic centimeters of the copper(II) sulfate solution, in order to precipitate copper(II) hydroxide.

  3. Add the freshly precipitated copper(II) hydroxide into the tube with  the previously prepared mixture of the solution of sucrose and hydrochloric acid.

  4. Heat the resulting mixture in the beaker with hot water.

  5. Observe the changes that occur.

Summary
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Observations (Uzupełnij). Conclusions (Uzupełnij).

What reactions occurred during the experiment?
The reaction of copper(II) sulphate with the sodium hydroxide solution produces copper(II) hydroxide.

CuSO+ 2NaOH → Cu(OH)2 NaSO4

As a result of heating, copper(II) hydroxide is decomposed into copper(II) oxide and water.

Cu(OH)temp  CuO + H2O

copper(II) hydroxide temp copper(II) oxide + water

Glucose reacts with copper(II) oxide.

C6H12O6 + 2CuOtemp  Cu2O + C6H12O7

glucose + copper(II) oxidetemp  copper(I) oxide + gluconic acid

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Film pokazuje eksperyment - badanie właściwości redukujących zhydrolizowanej sacharozy. Trommer's test for hydrolysed sucrose. W probówkach roztwór zhydrolizowanej sacharozy, siarczan sześć miedzi dwa oraz wodorotlenek sodu. Do probówki dodajemy kilka kropli siarczanu sześć miedzi dwa. Do niego dodajemy kilka kropli wodorotlenku sodu. Taki roztwór wlewamy do probówki z sacharozą. Podgrzewamy nad palnikiem. Zawartość probówki przyjmuje ceglastoczerwone zabarwienie.

Occurrence and use of sucrose

The bulbs of sugar beets and stems of sugarcanes are the main sources of sucrose. In small quantities, it may also be present in some fruit and vegetables.

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Occurrence of sucrose. Sugar beet, sugar cane, fruits, vegetables.
Source: Dariusz Adryan, licencja: CC BY 3.0.

Owing to its properties, sucrose has been used in many sectors of industry.

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Uses of sucrose. Food, confectionery, juices and syrups, medicine.
Source: Dariusz Adryan, licencja: CC BY 3.0.

Sugar – sweet poison

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1) When eating large amounts of sweets, we limit the consumption of fruits, vegetables and other valuable products. We deprive the body of vitamins and minerals in this way; 2) The can of a cola beverage contains about 12 teaspoons of sugar. Another ingredient is phosphoric acid, which contributes to to spoiling teeth
Source: OpenClipartVectors, Vectorscape, licencja: CC 0 1.0.

It is a well known fact that excessive amounts of sweets can lead to obesity. But is this the only effect? Excessive amount of sugars in our body is not recommended because it can cause many health issues, such as:

  • damage to the immune system,

  • disturbance of the mineral balance in the body,

  • increase in glucose and insulin levels,

  • vision impairment,

  • spoilage of teeth,

  • heart diseases,

  • raised cholesterol levels,

  • diabetes, and many others.

Excessive consumption of sugar has a negative effect on the brain tissue. Children and adolescents eating large amounts of sugar do not control their emotions, are nervous and aggressive. Sugar can also cause depression, irritation and fatigue. What's important, sugar can be addictive, much like nicotine and alcohol.

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Exercise 1
Wysłuchaj nagrania abstraktu, ułóż do niego pytania i zadaj je koledze.
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Exercise 2
Compound sugar belonging to the disaccharide group of the formula ce dwanaście ha dwadzieścia dwa o jedenaście; a white crystalline substance with a sweet taste; it dissolves well in water is called: Możliwe odpowiedzi: 1. sucrose, 2. fructose, 3. glucose

Conclusion

  • Sucrose is a disaccharide with the following formula: CIndeks dolny 12HIndeks dolny 22OIndeks dolny 11. It is a white, crystalline substance and has a sweet taste. It dissolves well in water.

  • Sucrose has no reducing properties and does not give a positive Trommer's test result.

  • In the human body, sucrose undergoes hydrolysis under the influence of enzymes and the hydrochloric acid – it decomposes into glucose and fructose.

  • Sucrose is present in sugar beets and sugarcanes. In smaller quantities, it may also be found in fruit and vegetables.

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Grafika przedstawiająca tablicę szkolną, na której znajdują się zdania do dokończenia. Finish selected sentences. 1 It was easy for me (uzupełnij). 2 It was difficult for me (uzupełnij). 3 Today I learned (uzupełnij). 4 I understood that (uzupełnij). 5 It surprised me (uzupełnij). 6. Today I found out (uzupełnij). 7. I was interested in (uzupełnij). 8. I still have to repeat (uzupełnij).
Source: GroMar Sp. z o.o., licencja: CC BY-SA 3.0.
Exercise 3
Sformułuj zagadkę odnoszącą się do porównania właściwości glukozy i sacharozy.
Sformułuj zagadkę odnoszącą się do porównania właściwości glukozy i sacharozy.

Keywords

sugars, disaccharides, sucrose, hydrolysis, molecular formula, reducing properties of sucrose

Glossary

sucrose
sucrose
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Nagranie słówka: sucrose

sacharoza – cukier złożony należący do grupy dwucukrów o wzorze CIndeks dolny 12HIndeks dolny 22OIndeks dolny 11; biała substancja krystaliczna o słodkim smaku; dobrze rozpuszcza się w wodzie