3.1.3 Lipids Flashcards

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1
Q

The 2 main groups of lipids that I need to know are… and…

A

Triglycerides
Phospholipids

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2
Q

The 2 main groups of lipids I need to know are triglycerides and…

A

Phospholipids

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3
Q

When drawing fatty acids, the letter ‘R’ represents….and is followed by COOH (carboxylic acid)

A

A long hydrocarbon chain

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4
Q

When drawing fatty acids, the letter ‘…’ represents a long hydrocarbon chain and is followed by COOH (carboxylic acid)

A

R

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5
Q

The role of triglycerides is…

A

Energy storage

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6
Q

True or false the ‘R’ group of a fatty acid (the long hydrocarbon chain) is always saturated

A

False, it can either be saturated or unsaturated

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7
Q

The…of a fatty acid can either be saturated or unsaturated

A

R-group

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8
Q

A condensation reaction between glycerol and a fatty acid forms a…bond

A

Ester

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9
Q

A…reaction between glycerol and a fatty acid forms an ester bond

A

Condensation

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10
Q

RCOOH represents….

A

A fatty acid
(Where R is the long hydrocarbon chain and COOH is the carboxylic acid)

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11
Q

RCOOH represents a fatty acid where R is the…and COOH is the…

A

Long hydrocarbon chain
Carboxylic acid

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12
Q

Triglycerides are formed by the condensation of on molecule of…and 3 molecules of…

A

Glycerol
Fatty acids

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13
Q

Triglycerides are formed by the condensation of one…of glycerol and 3…of fatty acid

A

Molecule(s)

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14
Q

Type of bond between fatty acid and glycerol

A

Ester

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15
Q

Saturated fatty acids vs unsaturated fatty acids

A

Saturated= no double carbon bond (form linear hydrocarbon chains)
Unsaturated= at least one double carbon bond (hydrocarbon chains can bend)

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16
Q

Which type of fatty acid out of saturated and unsaturated doesn’t contain any double carbon bonds

A

Saturated= no double carbon bonds

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17
Q

Which type of fatty acid out of saturated and unsaturated contains at least one double carbon bond

A

Unsaturated

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18
Q

Saturated fatty acids have no double carbon bonds so form hydrocarbon chains that are ….(what shape)

A

Linear

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19
Q

Unsaturated fatty acids have at least one double carbon bond so the hydrocarbon chains can…(think about the shape)

A

Bend

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20
Q

.. fatty acids form linear hydrocarbon chains but …..fatty acids form hydrocarbon chains that can bend

A

Saturated
Unsaturated

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21
Q

Triglycerides are…in water so are described as hydrophobic

A

Insoluble

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22
Q

Triglycerides are insoluble in water so are described as …

A

Hydrophobic

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23
Q

Triglycerides are insoluble in water so are described as …

A

Hydrophobic

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24
Q

The role of phospholipids is…

A

Structural role

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25
Q

In phospholipids, one of the fatty acids of a triglyceride is substituted by…

A

A phosphate containing group

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26
Q

…..are composed of glycerol, 2 fatty acids and a phosphate group

A

Phospholipids

27
Q

Phospholipids are the main component of …(part of cell)

A

Cell membrane

28
Q

…are the main component of cell membranes

A

Phospholipids

29
Q

True or false, phospholipids are fully hydrophobic

A

False
The fatty acids are hydrophobic
But the phosphate group is hydrophilic

30
Q

When drawing a phospholipid you draw a…head and…tails

A

Phosphate
Fatty acid

31
Q

During the condensation of a triglyceride (process of it being formed)…molecules of water are released and …ester bonds are formed

A

3

32
Q

During the condensation of a triglyceride…molecules of water are released

A

3

33
Q

During the condensation of a triglyceride…ester bonds are formed

A

3

34
Q

During the…of a triglyceride 3 molecules of water are released and 3 ester bonds are formed

A

Condensation

35
Q

When hydrolysed triglyceride is split by the addition of …water molecules

A

3

36
Q

Phospholipids form…in water where they position themselves so that the phosphate heads are as close to the water as possible and the fatty acid tails are as far from the water as possible

A

Bilayers

37
Q

Bilayer meaning

A

Where when placed in water phospholipids position themselves so that the phosphate heads are as close to the water as possible and the fatty acid tails are as far from the water as possible

(The arrangement of phospholipids in water)

38
Q

Triglycerides are made up of hydrogen, carbon and oxygen whereas phospholipids are made up of hydrogen, carbon, oxygen and also…

A

Phosphorus

39
Q

Triglycerides are hydrophobic whereas phospholipids are both hydrophobic and…

A

Hydrophilic
(The phosphate group (head) is hydrophilic but the fatty acids (tails) are hydrophobic)

40
Q

Phospholipids contain a …whereas triglycerides don’t

A

Phosphate group

41
Q

Triglycerides are made up of…fatty acids whereas phospholipids are made up of…fatty acids

A

3
2

42
Q

Both triglycerides and phospholipids have….(type of bond) bonds

A

Ester
(Between glycerol and fatty acid)

43
Q

Both triglycerides and phospholipids can have saturated or unsaturated…

A

Fatty acids
(The R group (long hydrocarbon chain) of fatty acids can be either saturated or unsaturated)

44
Q

In animal cells there is…embedded in the cell membrane to add stability

A

Cholesterol

45
Q

In animal cells there is cholesterol embedded in the cell membrane to add…

A

Stability

46
Q

Only animal cells have cholesterol embedded in the cell membrane to provide stability but not plant cells as plant cells also have a …

A

Cell wall

47
Q

You describe precipitates as c…but emulsions as m…

A

Cloudy
Milky

48
Q

You describe …as cloudy but…as milky

A

Precipitates
Emulsions

49
Q

Which out of a precipitate and emulsion can be filtered

A

Precipitate (where there’s a solid in a liquid)

(Emulsion is where there are tiny liquid droplets in a liquid)

50
Q

Method for emulsion test

A

1) Mix sample with 5cm cubed alcohol in a test tube
2) Shake thoroughly
3) Add 5cm cubed cold water and shake gently
4) Milky white emulsion formed indicates presence of lipid

51
Q

In the emulsion test which do you add first out of water and alcohol

A

Alcohol
(Add sample to test tube with 5cm cubed of alcohol and shake thoroughly then add 5cm cubed of water and shake gently)

52
Q

In the emulsion test which do you do first, shake gently or shake thoroughly

A

Thoroughly
(After adding sample and 5cm cubed of alcohol to test tube. Then add 5cm cubed water and shake gently)

53
Q

First stage of emulsion test

A

Add sample and 5cm cubed of alcohol to test tube and shake thoroughly
(Then add 5cm cubed water and shake gently and if lipid is present a milky white colour should form)

54
Q

In the emulsion test if lipid is present then a …emulsion should form

A

Milky white

55
Q

For the emulsion test as a control you should…

A

Repeat the whole procedure using just water and the solution should remain clear

56
Q

For the emulsion test as a control you should…

A

Repeat the whole procedure using just water and the solution should remain clear

57
Q

Why triglycerides are used as energy storage molecules

A

They contain lots of chemical energy (triglycerides are composed of long hydrocarbon chains in the fatty acid with lots of chemical bonds between carbon and hydrogen atoms and these bonds hold a large amount of energy)

They’re insoluble in water (

58
Q

Name of tissue (body fat) that triglycerides are stored in

A

Adipose

59
Q

True or false, plasma membrane and cell membrane are the same thing

A

True

60
Q

The centre of the bilayer in the cell membrane is… so water soluble substances can’t easily pass through it

A

Hydrophobic
(As all the hydrophobic fatty acid tails from the phospholipids are on the inside)

61
Q

What is the emulsion test on a food sample testing for

A

Presence of Lipids (fats)

62
Q

What is the emulsion test on a food sample testing for

A

Presence of Lipids (fats)

63
Q

True or false, both triglycerides and phospholipids are insoluble in water

A

True

64
Q

Explain why phospholipids can form a bilayer but triglycerides can’t (3 marks)

A

Phospholipids are both hydrophobic and hydrophilic so phosphate group attracts water to either side of the bilayer but triglycerides are only hydrophobic