1.3: Carbohydrates - disaccharides and polysaccharides Flashcards
Monosaccharides can also be combined in much larger numbers to form polysaccharides.
In carbohydrates, the monomer unit is called what?
In carbohydrates, the monomer unit is called a monosaccharide
Pairs of monosaccharides can also be combined to form a disaccharide.
For example, glucose joined to glucose forms what?
For example, glucose joined to glucose forms maltose
Pairs of monosaccharides can also be combined to form a disaccharide.
For example, glucose joined to fructose forms what?
For example, glucose joined to fructose forms sucrose
Pairs of monosaccharides can also be combined to form a disaccharide.
For example, glucose joined to galactose forms what?
For example, glucose joined to galactose forms lactose
Pairs of monosaccharides can also be combined to form a disaccharide.
When the monosaccharides join, a molecule of water is what?
When the monosaccharides join, a molecule of water is removed
Pairs of monosaccharides can also be combined to form a disaccharide.
When the monosaccharides join, a molecule of water is removed and the reaction is therefore called what?
When the monosaccharides join, a molecule of water is removed and the reaction is therefore called a condensation reaction
Condensation reaction
A condensation reaction is a chemical process in which 2 molecules combine to form a more complex one with the elimination of a simple substance, usually water
A condensation reaction is a chemical process in which 2 molecules combine to form a more complex one with the elimination of a simple substance, usually water.
Many what are formed by condensation reactions?
Many biological polymers are formed by condensation reactions
A condensation reaction is a chemical process in which 2 molecules combine to form a more complex one with the elimination of a simple substance, usually water.
Many biological polymers, such as what, are formed by condensation reactions?
Many biological polymers, such as:
- Polysaccharides
- Polypeptides
,are formed by condensation reactions
Pairs of monosaccharides can also be combined to form a disaccharide.
When the monosaccharides join, a molecule of water is removed and the reaction is therefore called a condensation reaction.
The bond that is formed is called what?
The bond that is formed is called a glycosidic bond
Pairs of monosaccharides can also be combined to form a disaccharide.
When the monosaccharides join, a molecule of water is removed and the reaction is therefore called a condensation reaction.
The bond that is formed is called a glycosidic bond.
When water is added to a disaccharide under suitable conditions, it does what?
When water is added to a disaccharide under suitable conditions, it breaks the glycosidic bond, releasing the constituent monosaccharides
Pairs of monosaccharides can also be combined to form a disaccharide.
When the monosaccharides join, a molecule of water is removed and the reaction is therefore called a condensation reaction.
The bond that is formed is called a glycosidic bond.
When water is added to a disaccharide under suitable conditions, it breaks the glycosidic bond, releasing the constituent monosaccharides.
What is this called?
This is called hydrolysis
Hydrolysis
Hydrolysis is the breaking down of large molecules into smaller ones by the addition of water molecules
Be clear about the difference between the terms ‘condensation’ and ‘hydrolysis.’
Both condensation and hydrolysis involve the use of water in reactions.
However, condensation is what, while hydrolysis is what?
- Condensation is the giving out of water in reactions
,while
- Hydrolysis is the taking in of water to split molecules in reactions
Some disaccharides, like maltose, are what?
Some disaccharides, like maltose, are reducing sugars
Some disaccharides, like maltose, are reducing sugars.
To detect these we use the Benedict’s test.
Other disaccharides, like sucrose, are known as what?
Other disaccharides, like sucrose, are known as non-reducing sugars
Some disaccharides, like maltose, are reducing sugars.
To detect these we use the Benedict’s test.
Other disaccharides, like sucrose, are known as non-reducing sugars, because they what?
Other disaccharides, like sucrose, are known as non-reducing sugars, because they do not change the colour of Benedict’s reagent when they are heated with it
Some disaccharides, like maltose, are reducing sugars.
To detect these we use the Benedict’s test.
Other disaccharides, like sucrose, are known as non-reducing sugars, because they do not change the colour of Benedict’s reagent when they are heated with it.
In order to detect a non-reducing sugar, it must first be what?
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis
Some disaccharides, like maltose, are reducing sugars.
To detect these we use the Benedict’s test.
Other disaccharides, like sucrose, are known as non-reducing sugars, because they do not change the colour of Benedict’s reagent when they are heated with it.
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be what?
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a:
- Pestle
- Mortar
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add what to what?
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in:
- A test tube
- Filter
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube where for how long?
Place the test tube in a gently boiling water bath for 5 minutes
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains what), then what?
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add what to what?
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube where for how long?
- Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube
- Place the test tube in a gently boiling water bath for 5 minutes
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will do what?
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides.
Slowly add what to what in order to neutralise the hydrochloric acid?
Slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides.
Why do you slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid?
Slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid, because Benedict’s reagent will not work in acidic conditions
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides.
Slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid, because Benedict’s reagent will not work in acidic conditions.
Test with what to check what?
Test with pH paper to check that the solution is alkaline
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides.
Slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid, because Benedict’s reagent will not work in acidic conditions.
Test with pH paper to check that the solution is alkaline.
Re-test the resulting solution by doing what?
Re-test the resulting solution by heating it with 2cm³ of Benedict’s reagent in a gently boiling water bath for 5 minutes
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides.
Slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid, because Benedict’s reagent will not work in acidic conditions.
Test with pH paper to check that the solution is alkaline.
Re-test the resulting solution by heating it with 2cm³ of Benedict’s reagent in a gently boiling water bath for 5 minutes.
If a non-reducing sugar was present in the original sample, the Benedict’s reagent will now do what?
If a non-reducing sugar was present in the original sample, the Benedict’s reagent will now turn orange-brown
In order to detect a non-reducing sugar, it must first be hydrolysed into its monosaccharide components by hydrolysis.
The process is carried out as if the sample is not already in liquid form, it must first be ground up in water with a pestle and mortar.
Add 2cm³ of the food sample being tested to 2cm³ of Benedict’s reagent in a test tube and filter.
Place the test tube in a gently boiling water bath for 5 minutes.
If the Benedict’s reagent does not change colour (the solution remains blue), then a reducing sugar is not present.
Add another 2cm³ of the food sample to 2cm³ of dilute hydrochloric acid in a test tube and place the test tube in a gently boiling water bath for 5 minutes.
The dilute hydrochloric acid will hydrolyse any disaccharide present into its constituent monosaccharides.
Slowly add some sodium hydrogencarbonate solution to the test tube in order to neutralise the hydrochloric acid, because Benedict’s reagent will not work in acidic conditions.
Test with pH paper to check that the solution is alkaline.
Re-test the resulting solution by heating it with 2cm³ of Benedict’s reagent in a gently boiling water bath for 5 minutes.
If a non-reducing sugar was present in the original sample, the Benedict’s reagent will now turn orange-brown.
The Benedict’s reagent now turning orange-brown if a non-reducing sugar was present in the original sample is due to what?
The Benedict’s reagent now turning orange-brown if a non-reducing sugar was present in the original sample is due to the reducing sugars that were produced from the hydrolysis of the non-reducing sugar
Polysaccharides are polymers, formed by combining together many monosaccharide molecules.
The monosaccharides are joined by glycosidic bonds that were formed by condensation reactions.
As polysaccharides are very large molecules, they are what?
As polysaccharides are very large molecules, they are insoluble
Polysaccharides are polymers, formed by combining together many monosaccharide molecules.
The monosaccharides are joined by glycosidic bonds that were formed by condensation reactions.
As polysaccharides are very large molecules, they are insoluble.
This feature makes them suitable for what?
This feature makes polysaccharides suitable for storage
Polysaccharides are polymers, formed by combining together many monosaccharide molecules.
The monosaccharides are joined by glycosidic bonds that were formed by condensation reactions.
As polysaccharides are very large molecules, they are insoluble.
This feature makes them suitable for storage.
When they are hydrolysed, polysaccharides do what?
When they are hydrolysed, polysaccharides break down into:
- Disaccharides
Or,
- Monosaccharides
Polysaccharides are polymers, formed by combining together many monosaccharide molecules.
The monosaccharides are joined by glycosidic bonds that were formed by condensation reactions.
As polysaccharides are very large molecules, they are insoluble.
This feature makes them suitable for storage.
When they are hydrolysed, polysaccharides break down into disaccharides or monosaccharides.
Some polysaccharides, such as cellulose, are what?
Some polysaccharides, such as cellulose, are not used for storage
Polysaccharides are polymers, formed by combining together many monosaccharide molecules.
The monosaccharides are joined by glycosidic bonds that were formed by condensation reactions.
As polysaccharides are very large molecules, they are insoluble.
This feature makes them suitable for storage.
When they are hydrolysed, polysaccharides break down into disaccharides or monosaccharides.
Some polysaccharides, such as cellulose, are not used for storage, but do what?
Some polysaccharides, such as cellulose, are not used for storage, but give structural support to plant cells
Polysaccharides illustrate an important principle, that a few basic monomer units can be what to give what?
Polysaccharides illustrate an important principle, that a few basic monomer units can be combined in a number of different ways to give a large range of different biological molecules
Starch is a polysaccharide that is found in many parts of plants in the form of what?
Starch is a polysaccharide that is found in many parts of plants in the form of small:
- Granules
Or,
- Grains
Starch is a polysaccharide that is found in many parts of plants in the form of small granules or grains.
Example
For example, starch grains in chloroplasts
Starch is a polysaccharide that is found in many parts of plants in the form of small granules or grains.
It is formed by what?
Starch is formed by the joining of between:
- 200
- 100,000
a-glucose molecules by glycosidic bonds in a series of condensation reactions
Starch is easily detected by its ability to do what?
Starch is easily detected by its ability to change the colour of the iodine in potassium iodide solution from:
- Yellow
to
- Blue-black
Starch is easily detected by its ability to change the colour of the iodine in potassium iodide solution from yellow to blue-black.
The test is carried out at what temperature?
The test is carried out at room temperature
Starch is easily detected by its ability to change the colour of the iodine in potassium iodide solution from yellow to blue-black.
The test is carried out at room temperature.
The test is carried out as you place what into a test tube or do what?
The test is carried out as you:
- Place 2cm³ of the sample being tested into a test tube
Or,
- Add 2 drops of the sample into a depression on a spotting tile
Starch is easily detected by its ability to change the colour of the iodine in potassium iodide solution from yellow to blue-black.
The test is carried out at room temperature.
The test is carried out as you place 2cm³ of the sample being tested into a test tube or add 2 drops of the sample into a depression on a spotting tile.
Add what and do what?
- Add 2 drops of iodine solution
- Shake or stir
Starch is easily detected by its ability to change the colour of the iodine in potassium iodide solution from yellow to blue-black.
The test is carried out at room temperature.
The test is carried out as you place 2cm³ of the sample being tested into a test tube or add 2 drops of the sample into a depression on a spotting tile.
Add 2 drops of iodine solution and shake or stir.
The presence of starch is indicated by a what?
The presence of starch is indicated by a blue-black coloration
The terms ‘condensation’ and ‘hydrolysis.’
Both involve the use of water in reactions.
However, condensation is the what of water in reactions, while hydrolysis is the what of water to split molecules in reactions?
- Condensation is the giving out of water in reactions
,while
- Hydrolysis is the taking in of water to split molecules in reactions
The function of glucose is that it is what?
The function of glucose is that it is the main sugar used in respiration
The function of glucose is that it is the main sugar used in respiration.
What are polymers of glucose?
- Starch
- Glycogen
are polymers of glucose
The function of glucose is that it is the main sugar used in respiration.
Starch and glycogen are polymers of glucose.
Glucose is what in the bloodstream to cells?
Glucose is:
- Absorbed
- Transported
in the bloodstream to cells
What is the function of galactose?
The function of galactose is that it is used mainly in our diet as part of the lactose disaccharide
What is the function of fructose?
The function of fructose is that it is a sugar found naturally in:
- Fruit
- Honey
- Some vegetables
What are monosaccharides used for in the body?
Monosaccharides are used to provide a rapid source of energy in the body
Monosaccharides are used to provide a rapid source of energy in the body.
Why are they so useful for this job?
Monosaccharides are so useful for this job, because they:
- Are readily absorbed
- Require little to no change for use in respiration
What is the function of sucrose?
The function of sucrose is that it is the form in which sugar is transported around the plant
Maltose is made of 2 glucose monomers.
When is maltose produced?
Maltose is produced when amylase breaks down starch
Why does it take us longer to use disaccharides in respiration?
It takes us longer to use disaccharides in respiration, because disaccharides need to be digested before they can be used to produce energy
It takes us longer to use disaccharides in respiration, because disaccharides need to be digested before they can be used to produce energy.
What are often stored in this form?
Sugars are often stored in this form
Like disaccharides, polysaccharides are formed by what?
Like disaccharides, polysaccharides are formed by condensation reactions
Polysaccharides are mainly used as what?
Polysaccharides are mainly used as:
- An energy store
- Structural components of cells
The major polysaccharides are what in plants and what in animals?
The major polysaccharides are:
- Starch and cellulose in plants
- Glycogen in animals
One role of lactose in living organisms
One role of lactose in living organisms is that it is the carbohydrate source in mammalian milk
