unit 2 Flashcards

1
Q

what is UV light?

A

high energy form of light present in sunglight

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2
Q

what can UV light do to molecules?

A

provide sufficient energy to break bonds within molecules and free radicals are formed

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3
Q

what effects does UV light have on the skin?

A

causes subrun
accelerates ageing of the skin

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4
Q

what can prevent UV light reaching the skin?

A

use sun-block

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5
Q

how are free radicals formed?

A

when UV light energy breaks bonds within molecules

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6
Q

what are free radicals?

A

atoms or molecules that are highly reactive due to the presence of unpaired electrons

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7
Q

steps of a free radical chain reaction

A

initiation
propagation
termination

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8
Q

what are free radical scavengers?

A

molecules that react with free radicals to form stable molecules

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9
Q

where can free radical scavengers be found?

A

cosmetics
food products
plastics

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10
Q

what are essential oils?

A

concentrated extracts of the volatile, non-water soluble aroma compounds from plants

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11
Q

where are essential oils used?

A

perfumes
cosmetic products
cleaning products
flavourings in foods

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12
Q

what are terpenes?

A

isoprene units joined together
unsaturated

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13
Q

systematic name for isoprene?

A

2-methylbuta-1,3-diene

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14
Q

draw the structure of isoprene

A

search it upppppppppppp

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15
Q

what can terpenes be oxidised to produce?

A

aromas of spices

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16
Q

what are proteins involved in?

A

maintenance and regulation of life processes

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17
Q

what are enzymes?

A

biological catalysts

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18
Q

what are proteins made of?

A

amino acids

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19
Q

what functional groups do amino acids contain?

A

amine group
NH2
carboxyl group
COOH

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20
Q

how are proteins made?

A

condensation

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21
Q

what functional group is found in a protein?

A

peptide link
-CONH-

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22
Q

what are essential amino acids?

A

must be required from the diet as the body cannot make them

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23
Q

what happens to proteins during digestion?

A

hydrolysis

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24
Q

structural formula amino acid
structural formula protein

A

search it upppppppppp

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25
Q

protein structure

A

long-chain molecules forming spirals held together by intermolecular bonding

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26
Q

what happens when a protein is heated?

A

intermolecular bonds are broken and proteins change shape (denature)

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27
Q

what is the result of a protein denaturing in food?

A

change in texture when its cooked

28
Q

how is soap produced?

A

alkaline hydrolysis of edible fats and oils

29
Q

what does alkaline hydrolysis produce?

A

3 fatty acid (soap)
1 glycerol

30
Q

how are the 3 fatty acid molecules changed into soap?

A

neutralised by the alkali forming ionic salts called soaps

31
Q

soap structure?

A

TAIL
non-polar
soluble in grease/oil
hydrophobic
HEAD
ionic
soluble in water
hydrophilic
negatively charged

32
Q

soap usage steps

A

1 - when mixed with grease/oil the hydrophobic tail dissolves in grease and hydrophilic head dissolved in water
2 - agitation results in ball-like structures with the hydrophobic tails on inside (vise versa)
3 - negatively charged micelles repel each other and oil/grease is suspended in water

33
Q

what is hard water

A

water containing high levels of dissolved metal ions

34
Q

how is scum formed?

A

mixing together hard water and soap

35
Q

what do soapless detergents do?

A

do not form scum with hard water
(same structure as soap)

36
Q

what is an emulsifier?

A

prevent non-polar and polar liquids separating into layers

37
Q

what is an emulsion?

A

contains small droplets of one liquid dispersed in another liquid

38
Q

how are emulsifiers used?

A

reacting edible oils with glycerol
only 1or2 fatty acid groups are linked to the glycerol
(works same as soap too)

39
Q

functional group found in an ester?

A

ester link
-COO-

40
Q

what are esters used for?

A

flavourings
fragrances
solvents for non-polar compounds

41
Q

how are esters formed?

A

condensation
alcohol+carboxylic acid

42
Q

what is a condensation reaction?

A

two molecules are joined together with the elimination of a small molecule (usually water)

43
Q

what is hydrolysis?

A

a molecule reacts with water to break down into smaller molecules

44
Q

how are fats and oils created?

A

condensation of glycerol (alcohol) and 3 fatty acids (carboxylic acid)

45
Q

glycerol name?

A

propane-1,2,3-triol

46
Q

glycerol structure

A

search it uppppppppp

47
Q

why do oils have a lower melting point than fats?

A

contain C=C meaning they cannot pack closely together so weaker intermolecular forces

fats contain no C=C

48
Q

how to test for the degree of saturation?

A

titration -
the greater number of C=C present, the more bromine solution can be decolourised

49
Q

what are fats and oils?

A

concentrated source of energy
essential for the transport and storage of fat-soluble vitamins in the body

50
Q

metal oxide + carboxylic acid =

A

salt + water

51
Q

metal hydroxide + carboxylic acid =

A

salt + water

52
Q

metal carbonate + carboxylic acid =

A

salt + water + carbon dioxide

53
Q

types of alcohol

A

primary
secondary
tertiary

54
Q

primary alcohol identification

A

the hydroxyl group is attached to a carbon which is attached to 1 other carbon

55
Q

secondary alcohol identification

A

the hydroxyl group is attached to a carbon which is attached to 2 other carbon

56
Q

tertiary alcohol identification

A

the hydroxyl group is attached to a carbon which is attached to 3 other carbon

57
Q

oxidation ratio

A

increase in the oxygen to hydrogen ratio

58
Q

reduction ratio

A

decrease in the oxygen to hydrogen ratio

59
Q

aldehyde and ketone functional group

A

carbonyl
–C=O

60
Q

oxidising agents for primary and secondary alcohols

A

acidified potassium dichromate
hot copper oxide

61
Q

acidified potassium dichromate colour change

A

orange - green

62
Q

hot copper oxide colour change

A

black - copper red

63
Q

oxidising agents for aldehydes

A

acidified potassium dichromate
fehling’s solution
tollens’ reagent

64
Q

fehling’s solution colour change

A

blue - brick red

65
Q

tollens’ reagent colour change

A

colourless and clear - silver mirror