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Flashcards in Nature's Chemistry Deck (114):
1

Carboxylic acids contain which functional group?

Carboxyl functional group

2

Carboxyl functional group has the structure?

COOH

3

Carboxylic acids react with bases to form? 

Salts

4

An ester can be identified by?

The ester group (RCOOR)Name ending in -yl -oate

5

First part of ester name (-yl) comes from?

Alcohol used to make it 

6

Second part of ester name (-oate) comes from?

The carboxylic acid

7

Esters have a characteristic?

Sweet' fruity smell

8

Uses of esters

PerfumesFlavouringsIndustrial Solvents

9

Esters are formed by?

A condensation reaction between a carboxylic acid and an alcohol

10

The ester link is formed by?

The reaction of a carboxyl group and a hydroxyl group

11

What is a condensation reaction?

One where molecules join together with the elimination of a samll molecule (normally water)

12

Esters can be hydrolysed to?

Produce a carboxylic acid and an alcohol

13

What is a hydrolysis reaction?

When a molecule reacts with water to give smaller molecules

14

Fats and oils are a concentrated source of?

Energy

15

Fats and oils are essential for?

The transport and storage of fat-soluble vitamins in the body

16

Fats and oils are?

Esters

17

Fats and oils ae formed from?

The condensation of glycerol and three carboxylic acid molecules

18

Glycerol is also known as?

Propan-1'2'3'-triol

19

Carboxylic acids used to form fats and oils are known as?

Fatty acids

20

Fatty acids are?

Saturated or unsaturated straight-chain carboxylic acids' usually with long chains of carbon atoms

21

The lower melting points of oils compared to those of fats is related to?

The high degree of unsaturation of oil molecules

22

The lower melting points of oils are a result of?

The effect that the shapes of the molecules have on close packing and thus the strength of the van der Waals' forces

23

Oils can be converted to fats by?

Hydrogenation

24

Hydrogenation of oils leads to a decrease in?

The number of carbon-carbon double bons

25

Hydrogenation of oils leads to an increase in?

The melting point of the oil

26

Proteins  are?

The major structural materials of animal tissue

27

Proteins are involved in

The maintenance and regulation of life processes

28

Enzymes are?

Proteins which act as biological catalysts

29

Within proteins the long-chain molecules may be?

Twisted to form spiralsFolded into sheetsWound round to form other complex shapes

30

Proteins can be?

Fibrous or Globular

31

Protein chains are held in shape by?

Intermolecular bonding between the side chains of constituent amino acids

32

If temperature increases or pH changes beyond a critical level the shape of the enzyme molecule is?

Irreversibly altered though the peptide links remain intact

33

If the active site of the enzyme has chained shape it is said to be?

Denatured

34

Amino acids are ?

The building blocks from which proteins are formed.

35

Amino acids contain both?

An amino group (NH2)Carboxyl Group (COOH)

36

Amino acids used to make proteins are all?

α-Amino acids

37

α-amino acids have?

Tje carboxyl group and amino group attached to the same carbon

38

An essentail amino acid is?

One which cannot be made in our body so must be supplied by our diet

39

Proteins are made of many?

Amino acids linked together by condensation reactions. 

40

In condensation reactions between amino acids?

The amino group on one amino acid and the carboxyl group on a neighbouring amino acid join together eliminating water

41

The link which forms between two amino acids is?

An amide link (CONH)Also called peptide link

42

Proteins which fulfil different roles in the body are formed by?

Linking differing sequences of amino acids together

43

During digestion' enzyme hydrolysis of dietary proteins produces?

Amino acids

44

Amino acids present in a protein can be identified by?

Hydrolysing the protein (Uaing acid) and then using chromatography.Application of known amino acids to the chromatogram alongside hydrolysed protein allows amino acids to be identified

45

Aldehydes and ketones both contain?

The carbonyl functional group (CO)

46

Aldehydes have the carbonyl group at?

The end of a chain

47

Ketones have the carbonyl group?

Not at the end of a chain

48

Aldehydes can be identified by?

Its '-al' end

49

Ketones can be identified by their?

-one' ending

50

Aldehydes that onlay contain C-C single bonds are called?

Alkanals

51

Ketones that only contain C-C single bonds are called?

Alkanones

52

Aldehydes can be oxidised to?

Carboxylic acids

53

Indicators used to differentiate between an aldehyde and ketone

Acidified dichromateBenedict's solutionTollens' reagent

54

Acidified dichromate turns from?

Orange to green

55

Benedict's solution turns from?

Blue solution to a red precipitate

56

Tollen's regeant turns from?

A colourless solution to a silver mirror

57

The majority of what we describe as flavour comes from?

Odour identified by nasal cells

58

Flavour molecules are wafted?

Up the mouth

59

Flavours of foods are due to the presence of?

Volatile organic molecules

60

By looking at functional groups present in flavour molecules it is possible to suggest?

Wether they are likely to be water soluble or oil soluble

61

Looking at the size of the molecule and functional groups present allows predictions to be made about?

The boiling point and hence the volatility of flavour molecules

62

When proteins are heated?

The intermolecular bonds are broken allowing proteins to change shape

63

Changes to the shape of proteins alters?

The texture of foods

64

Alcohols can be identified fom?

The hydroxyl functional group (-OH)'-ol' name ending

65

Alcohols that only contain C-C double bonds are celled?

Alkanols

66

Hydrogen bonds found in alcohols explain?

Solubility in waterHigher boiling point

67

In alcohols hydrogen bonding increases with?

An increase in the number of hydroxyl groups

68

Triols are more viscous than?

diols and monols

69

When drawing the full structural formula of an alcohol the hydroxyl group must be shown?

-O-H and Not -OH

70

An alcohol may be (Depending on structure)?

Primary' secondary or tertiary

71

Primary alcohols (Oxidation)

Oxidised to an aldehyde then to a carboxylic acid

72

Secondary alcohols (Oxidation)

Oxidised to ketones

73

Tertiary alcohols (Oxidation)

Cannot be oxidised

74

Hot copper(II) oxide or acidified dichromate solutions can be used to oxidise?

Primary and secondary alcohols

75

When copper(II) oxide oxidisises an alcohol it turns from?

Black to brown

76

Carboxylic acids (Reduction)

First to aldehyde then to primary alcohol

77

Oxidation results in (O:H ratio)

Increase in oxygen to hydrogen ratio

78

Reduction causes (O:H ratio)

Decrease

79

Oxygen reacts with edible oils giving the food a?

Rancid flavour

80

Antioxidants are?

Molecules which prevents oxidation of edible oils

81

Ion-electron equations can be written for the oxidation of?

Many antioxidants

82

The alkaline hydrolysis of fats and oils forms?

Water-soluble ionic salts called soaps

83

Structure of soap ion

Long covalent tail (hydrophobic)Ionic Carboxylate head (Negatively charged and hydrophilic)

84

Detergents are similar to?

Soaps but have different hydrophilic heads

85

Detergents are particularly useful in?

Hard water areas

86

During cleaning using soaps and detergents?

Hydrophobic tails dissolve in oil/greaseHydrophilic heads face outwardsBall-like structure forms Repulsion between charges results in emulsion being formed and dirt-released

87

An emulsion contains?

Small droplets of one liquid dispersed in another liquid

88

Emulsions in food are mixtures of?

Oil and water

89

Emulsion: To prevent oil and water components seperating into layers?

An emulsifier is added

90

Emuslifiers for use in food are commonly made by?

Reacting edible oils with glycerol to formrm molecules where one or two fatty acids are linked to a glycerol backbone

91

Fatty acid chains are (Emulsions)?

Hydrophobic

92

Essential Oils are?

Concentrated extracts of volatile 'non-water soluble aroma compounds from plants

93

Essential Oils are mixtures of?

Organic compounds

94

Essential oils are generally extracted by?

Steam distillation or solvent extraction

95

Essential oils are widely used in?

Perfumes' cosmetics' cleaning products and flavourings

96

Terpenes are key components in?

Most essential oils

97

Terpenes are?

Unsaturated compounds formed from units of isoprene

98

Isoprene

2-methylbuta-1'3-diene   C5H8

99

The basic molecular formulae of terpenes are?

Multiples of C5H8 (C5H8)n

100

Isoprene units may be linked together to form?

Chains or rings

101

The isoprene unit is one of?

Nature's most common building blocks

102

Terpenes are components in a wide variety of?

Fruit and floral flavours and aromas

103

Terpenes can be oxidised within plants to produce?

Some of the compounds responsible for the distinctive aroma of spices

104

Ultraviolet radiation is?

A high-energy form of light' present in sunlight

105

Exposure to UV light can result in?

Molecules gaining sufficient energy for bonds to be broken. (Process responsible for sunburn)

106

Sunblock prevents?

UV light reaching the skin

107

When UV light breaks bonds what are formed?

Free Radicals

108

What is homolytic fission?

When a bond splits evenly' with each atom getting one of the shared pair of electrons to give two free radicals

109

Free readicals have an unpaired electron so?

Are highly reactive

110

Steps of a free radical chain reaction?

InitiationPropagationTermination

111

Many cosmetic products contain?

Free radical scavengers

112

Free radical scavengers are?

Moleciules which can react with free radicals to form stable molecules and prevent chain reactions

113

Free radical scavengers are added to?

Food productsPlasticsCosmetic products

114

Examples of natural free radical scavengers

MelatoninVitamin EBeta Carotene