What are polymers? Polymers are molecules made from a large number of monomers
joined together
What are monomers? Monomers are the smaller units from which larger molecules are made.
Which monomers are carbohydrates made from? monosaccharides
Give three examples of carbohydrate monomers glucose, fructose, galactose
What are the two types of glucose alpha and beta glucose
Draw alpha glucose
Draw beta glucose
What is a condensation reaction? When two molecules join together to form a bond
releasing a water molecule.
( bond can be glycosidic , ester or phosphodiester )
What joins monosaccharides together and what is formed? condensation reactions anda
disaccharide is formed
What makes maltose? glucose and glucose
What makes sucrose? glucose and fructose
What makes lactose? glucose and galactose
What can break polymers into monomers? a hydrolysis reaction
What is a hydrolysis reaction? Breaks the chemical bond between monomers using a
water molecule.
What do you use to test for sugars? Benedicts test
Which types of sugars are there? reducing and non reducing
Name a reducing sugar glucose
name a non reducing sugar sucrose
describe a Benedict's test for reducing sugars Add Benedict's reagent
Heat it in a water bath that has been brought to boil
If its positive : blue to a coloured precipitate ( green -> yellow
-> orange -> brick red )
describe a test for non reducing sugars Add dilute HCl
Heat in a water bath thats been brought to boil
Neutralise it with sodium hydrogencarbonate
Then carry it out as you would for a reducing sugar
- Add Benedict's reagent
- Heat in a water bath thats been brought to boil
If positive: blue to a coloured precipitate ( green -> yellow
-> orange -> brick red )
If a test is negative for a reducing sugar. what should you do? Still test it for a non
reducing sugar
What is a polysaccharide? Polysaccharides are formed by the condensation of many
glucose units/ molecules.
What is starch made from? Two polysaccharides of alpha glucose:
- amylose
-amylopectin
What are the features of amylose? - long unbranched chain of alpha glucose
- coiled structure -> compact -> good for storage -> fit more in a given space
What are the features of amylopectin? - long branched chain of alpha glucose
- side branches allow enzymes to break glycosidic bonds easily -> glucose can be released
quickly
What other property makes starch good for storage? - insoluble in water
- doesn't affect water potential
, - prevents osmotic damage
How do we test for starch? Iodine test
- add iodine dissolved in potassium iodide solution
- Positive result: brown/black to a blue-black colour
What is glycogen? Polysaccharide of alpha glucose
What are the properties of glycogen? - highly branched ( more than amylopectin ) -> easily
broken down -> glucose can be released quickly -> important for energy release
- compact -> good for storage
What is cellulose made from? long unbranched chains of beta glucose
What happens to beta glucose molecules in a condensation reaction? The second / every
second beta glucose molecule is 'flipped' or inverted
What are microfibrils? Cellulose chains linked together by hydrogen bonds
How do microfibrils help cellulose? Provide structural support
What are the two types of lipid? Phospholipids and triglycerides
How are triglycerides formed?
Draw their sturcture. formed by the condensation of one molecule of glycerol and three
molecules of fatty acid. One molecule of water is released for each ester bond formed.
What bond is formed in a triglyceride? an ester bond - between the glycerol and fatty
acid
( 3 altogether )
What is the structure of a fatty acid?
What are the properties of a fatty acid? Hydrophobic tail - repels water
Hydrophilic head - attracts water
Draw the formation a triglyceride
What are the types of fatty acids and give the difference. Unsaturated fatty acid - double
bond
saturated fatty acid - single bond
What is the structure of a phospholipid?
Draw it. A hydrophilic phosphate group attached to a glycerol.
The glycerol is attached to two hydrophobic fatty acid tails.
What are triglycerides used for? Energy storage molecules
What are the properties of a triglyceride and how does this help their function? - Long
hydrocarbon tails contain lots of energy -> lots of energy released when they are broken
down -> contain 2x energy per gram as carbohydrates
- Insoluble -> do not affect water potential -> prevents osmotic damage
- Clump together to form insoluble droplets -> hydrophobic fatty acid tails which face
inwards
What are the properties of a phospholipid and how does this help their function?
Hydrophilic heads and hydrophobic tails -> form a double layer with the tails facing
inwards
therefore the center is hydrophobic so water soluble substances can not pass through -
membrane acts as a barrier to these substances.
Where are phospholipids found and what does it do? Phospholipids make up the
bilayer of cell membranes and they control what enters and leaves a cell
How do we test for lipids? Emulsion test:
- add ethanol and shake so it fully dissolves
- pour the solution into water
Positive result: milky emulsion
What are the differences between a phospholipid and triglyceride? - Phospholipid has 2 fatty
acid tails whereas a triglyceride has 3
joined together
What are monomers? Monomers are the smaller units from which larger molecules are made.
Which monomers are carbohydrates made from? monosaccharides
Give three examples of carbohydrate monomers glucose, fructose, galactose
What are the two types of glucose alpha and beta glucose
Draw alpha glucose
Draw beta glucose
What is a condensation reaction? When two molecules join together to form a bond
releasing a water molecule.
( bond can be glycosidic , ester or phosphodiester )
What joins monosaccharides together and what is formed? condensation reactions anda
disaccharide is formed
What makes maltose? glucose and glucose
What makes sucrose? glucose and fructose
What makes lactose? glucose and galactose
What can break polymers into monomers? a hydrolysis reaction
What is a hydrolysis reaction? Breaks the chemical bond between monomers using a
water molecule.
What do you use to test for sugars? Benedicts test
Which types of sugars are there? reducing and non reducing
Name a reducing sugar glucose
name a non reducing sugar sucrose
describe a Benedict's test for reducing sugars Add Benedict's reagent
Heat it in a water bath that has been brought to boil
If its positive : blue to a coloured precipitate ( green -> yellow
-> orange -> brick red )
describe a test for non reducing sugars Add dilute HCl
Heat in a water bath thats been brought to boil
Neutralise it with sodium hydrogencarbonate
Then carry it out as you would for a reducing sugar
- Add Benedict's reagent
- Heat in a water bath thats been brought to boil
If positive: blue to a coloured precipitate ( green -> yellow
-> orange -> brick red )
If a test is negative for a reducing sugar. what should you do? Still test it for a non
reducing sugar
What is a polysaccharide? Polysaccharides are formed by the condensation of many
glucose units/ molecules.
What is starch made from? Two polysaccharides of alpha glucose:
- amylose
-amylopectin
What are the features of amylose? - long unbranched chain of alpha glucose
- coiled structure -> compact -> good for storage -> fit more in a given space
What are the features of amylopectin? - long branched chain of alpha glucose
- side branches allow enzymes to break glycosidic bonds easily -> glucose can be released
quickly
What other property makes starch good for storage? - insoluble in water
- doesn't affect water potential
, - prevents osmotic damage
How do we test for starch? Iodine test
- add iodine dissolved in potassium iodide solution
- Positive result: brown/black to a blue-black colour
What is glycogen? Polysaccharide of alpha glucose
What are the properties of glycogen? - highly branched ( more than amylopectin ) -> easily
broken down -> glucose can be released quickly -> important for energy release
- compact -> good for storage
What is cellulose made from? long unbranched chains of beta glucose
What happens to beta glucose molecules in a condensation reaction? The second / every
second beta glucose molecule is 'flipped' or inverted
What are microfibrils? Cellulose chains linked together by hydrogen bonds
How do microfibrils help cellulose? Provide structural support
What are the two types of lipid? Phospholipids and triglycerides
How are triglycerides formed?
Draw their sturcture. formed by the condensation of one molecule of glycerol and three
molecules of fatty acid. One molecule of water is released for each ester bond formed.
What bond is formed in a triglyceride? an ester bond - between the glycerol and fatty
acid
( 3 altogether )
What is the structure of a fatty acid?
What are the properties of a fatty acid? Hydrophobic tail - repels water
Hydrophilic head - attracts water
Draw the formation a triglyceride
What are the types of fatty acids and give the difference. Unsaturated fatty acid - double
bond
saturated fatty acid - single bond
What is the structure of a phospholipid?
Draw it. A hydrophilic phosphate group attached to a glycerol.
The glycerol is attached to two hydrophobic fatty acid tails.
What are triglycerides used for? Energy storage molecules
What are the properties of a triglyceride and how does this help their function? - Long
hydrocarbon tails contain lots of energy -> lots of energy released when they are broken
down -> contain 2x energy per gram as carbohydrates
- Insoluble -> do not affect water potential -> prevents osmotic damage
- Clump together to form insoluble droplets -> hydrophobic fatty acid tails which face
inwards
What are the properties of a phospholipid and how does this help their function?
Hydrophilic heads and hydrophobic tails -> form a double layer with the tails facing
inwards
therefore the center is hydrophobic so water soluble substances can not pass through -
membrane acts as a barrier to these substances.
Where are phospholipids found and what does it do? Phospholipids make up the
bilayer of cell membranes and they control what enters and leaves a cell
How do we test for lipids? Emulsion test:
- add ethanol and shake so it fully dissolves
- pour the solution into water
Positive result: milky emulsion
What are the differences between a phospholipid and triglyceride? - Phospholipid has 2 fatty
acid tails whereas a triglyceride has 3
