Question 1

The structure of phospholipids includes the following

1 - polar phosphate heads

2 - hydrophobic fatty acid chains

3 - saturated fatty acid chains

Which of these are essential for the formation of a phospholipid bilayer in a cell-surface membrane?

  A  

1 and 2

  B  

1 and 3

  C  

2 and 3

  D  

3 only

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Question 2

Which formula(e) of fatty acids represents a saturated fatty acid?

1 - palmitic acid, C15H31COOH

2 - oleic acid, C17H33COOH

3 - linoleic acid, C17H31COOH

  A  

1, 2, and 3

  B  

only 1 and 2

  C  

only 2 and 3

  D  

only 1

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Question 3

Linseed oil is a polyunsaturated triglyceride that can be extracted from the seeds of the flax plant, Linum usitatissimum.

A diagram of a linseed oil molecule is shown below.

Which option correctly identifies the bond labelled W?

  A  

glycosidic

  B  

phosphodiester

  C  

peptide

  D  

ester


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Question 4

Cholesterol is an integral component of the cell-surface membrane.

Which statement about cholesterol is correct?

  A  

it allows ions to pass freely through the cell-surface membrane

  B  

it has a hydrophobic head and a hydrophilic tail

  C  

it helps to regulate the fluidity of the cell-surface membrane

  D  

it reduces the mechanical stability of the phospholipid bilayer

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Question 5

In unsaturated lipid molecules, where are double bonds located?

  A  

between fatty acids and glycerol

  B  

within fatty acids and within glycerol

  C  

within fatty acids only

  D  

within glycerol only

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Question 6

The diagram shows a triglyceride molecule that has been partially hydrolysed.

What will be the products of the total hydrolysis of the molecule shown?

  A  

a molecule of glycerol and a saturated fatty acid molecule only

  B  

a molecule of glycerol and an unsaturated fatty acid molecule only

  C  

a molecule of water, a molecule of glycerol and a saturated fatty acid molecule

  D  

a molecule of water, a molecule of glycerol and an unsaturated fatty acid molecule

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Question 7

Which statement about triglycerides is correct?

  A  

they are made up of three fatty acids combined with glycogen


  B  

they are more saturated with hydrogen compared with phospholipids

  C  

they form a bilayer in the cell surface membranes of cells

  D  

they have a lower ratio of oxygen to carbon compared with carbohydrates

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Question 8

Which option is a type of reaction involved in the breakdown of a phospholipid?

  A  

condensation

  B  

dehydrogenation

  C  

hydrolysis

  D  

phosphorylation

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Question 9

Which option is a property of the phosphate group in phospholipids?

  A  

hydrophilic

  B  

hydrophobic

  C  

non-polar

  D  

saturated

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Question 10

How many fatty acid residues are normally present in a phospholipid molecule?

  A  

1

  B  

2

  C  

3

  D  

4

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Question 11

Some foods contain ‘hydrogenated vegetable oils’. These are unsaturated fats that have been

converted to saturated fats.

Which property of the fats will have changed?

  A  

their hydrocarbon chains will fit together more closely

  B  

their solubility in water will increase

  C  

they will have more double bonds in their molecules

  D  

they will remain liquid at room temperature

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