Lipids Flashcards
What are the main uses of lipids ?
Lipids are used in the neurone is to increase rate of reactions in the myelin sheath.
Waterproofing in the waxy cuticle of leaves.
How is a triglyceride formed ?
Formed by a condensation reaction.
The hydroxide from the glycerol and the hydrogen from a fatty acid bond to create water which is then expelled.
As Ester bond replaces the water. Jks happens three times therefore meaning that 3 water molecules are formed during production of a triglyceride.
How many water molecules are made during the production a triglyceride.
3
Draw the structure of glycerol.
X
What components are in a fatty acid.
Carbonyl group and fatty acid tail.
What does r mean on a fatty acid.
Variable reaching in the structure of a fatty acid.
What is a saturated fatty acids.
All single carbon bonds.
What are unsaturated fatty acids.
Double carbon bonds.
What does monounsaturated mean ?
1 double carbon bond in the chain.
What does polyunsaturated mean ?
More than one double carbon bond in a chain.
What does ‘Cis’ isomeration mean ?
Both hydrogen’s are on the same side of the chain.
Attached to the double bond.
What is trans isomerism ?
Draw a diagram to explain
Hydrogen’s are on different sides of the double carbon bond.
What are the characteristics of lipids ?
They are non soluble and not considered polymers as long lipid chains cannot be formed.
Define fatty acid.
Fatty acid hydroxide tail and a carboxyl group.
Define saturated fatty acids.
All single carbon to carbon bonds.
Give examples of lipids.
Phospholipids and Triglycerides.
Exmplain why triglycerides are not considered to be polymers.
Long polymer chains Cannot be created as 3 fatty acids attach to create an Ester bond.
Describe a test you could carry out to show that a piece of coconut contains lipids.
Crush the coconut in ethanol and add to water.
A white emulsion will be produced if lipids are present.
Describe how a phospholipid differs from a triglyceride.
Phospholipid has a phosphate and only two fatty acids.
Give ways starch molecules are adapted for their function in a plant cell.
They are insoluble and therefore don’t affect water potential.
They are helical and compact.
They are large molecules and therefore can’t leave the cells.
Explain how cellulose molecules are adapted for their functions in plant cells.
They are long and straight chains that become linked together by many hydrogen bonds o form fibrils. This provides strength for the cell wall.
Name the reaction that breaks carbohydrates down into their monomers.
Hydrolysis.
Give features of starch and explain how this helps it act as a storage substance.
They are helical shaped so are therefore compact and tightly packed so lots can fit into a small place.
They are insoluble so have no somatic effect and don’t leave the cell or affect water potential.
Explain one way in which the structure of cellulose is linked to its function.
It has a glycosidic beta 1-4 bond
Why is sucrose classified as a carbohydrate ?
Carbon and hydrogen are in a 2:1 ratio which is the same proportions as in water.
What type of reaction breaks down sucrose into monosaccharides ?
Hydrolysis.
How does the test for lipids Work ?
Lipids dissolve in ethanol due to being soluble in alcohol
But then form a white precipitate in water due to being insoluble in water.
