Unit 4 AOS 2 Flashcards Preview

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Flashcards in Unit 4 AOS 2 Deck (141):
1

What is food needed for in the body

energy, growth, regulating body processes

2

What are the major food groups needed for the body

proteins, carbohydrates, fats and oils, vitamins and minerals

3

What are proteins needed for

growth, repair, immunity, transport of molecules,

4

Examples of what proteins are used for

hormones, enzymes, cellular structures (e.g. cell membrane, muscles), to transport molecules in the body, antibodies

5

What are carbohydrates needed for

to store and provide energy, functioning in nervous system

6

What are fats and oils needed for

insulation, to store some vitamins, to provide energy, in cell membranes

7

Define proteins

large molecules composed of one or more long chains of amino acids.

8

What are the monomers of proteins

amino acids

9

How many amino acids are there in the body

20

10

Can all these 20 amino acids be made by the body

no

11

How do we get amino acids that can’t be made in our body

through our food

12

What are essential amino acids

amino acids that cannot be synthesised by animals from materials in their diets and therefore must be supplied directly in the diet.

13

What elements make up amino acids

C, H, O, N and sometimes S and P

14

What are the amino acids used to synthesise proteins in the body called

2-amino acids or alpha amino acids

15

What is the structure of amino acids

CH, R, COOH, NH2

16

What properties can the R chain have

polar, non-polar, acidic or basic

17

Are amino acids soluble and why

they are soluble as they can form H bonds with water

18

Can amino act as acids, bases or both

both

19

What can amino acids act as

dipolar ions/zwitterions

20

What is a zwitterion

contain equal positive and negative charges

21

What does an amino acid look like as a zwitterion

NH3+ and COO-

22

When does an amino acid act as a zwitterion

pure solid state and in aqueous solutions in neutral pH, e.g. water

23

What will happen to amino acid in acidic environment

will act as base and so will have NH3+ with COOH

24

What will happen to amino acid in basic environment

will act as an acid and so will have NH2 and COO-

25

What is a sequence of amino acids called

a peptide chain

26

Between what molecules is the bond in a peptide chain

between the CO and the NH2 (O=C-N-H)

27

What is the bond in a peptide chain called

peptide bond

28

What is the name of the link between the C and the N

amide linkage

29

When is a polypeptide called a protein

more than 50 amino acids/ molar mass >5000gmol-1

30

How do you name a polypeptide (3)

by the sequence of amino acids from which they are made - which amino acid it derived from and put the abbreviation and then just put a dash to the next one, and it is written from left to right

31

Where is the N-terminus in a polypeptide chain

left side

32

Where is the C-terminus in a polypeptide chain

right side

33

What is the amino acids components of a polypeptide called

amino-acid residue

34

Define polypeptide

many amino acid residues bonded together.

35

Define primary structure

the order of amino acids in a polypeptide chain

36

Define secondary structure

structure formed folding of the polypeptide chain due to hydrogen bonding between carboxyl and amino groups in a protein molecule.

37

Important to note about secondary structure

the hydrogen bonding is at different positions of the chain

38

What causes alpha helices

H bonding between partially partially positive NH group and the partially negative COOH

39

What causes beta pleated sheet

H bonding between peptide links

40

Define tertiary structure

3D structure formed from side-group interaction, including hydrogen bonding, ionic bonding, dipole–dipole interactions and disulfide bridges

41

Define quaternary structure

multiple polypeptide chains joined together

42

Define denaturation

loss of structure or function of a protein

43

What causes denaturation

pH changes and heat

44

Why do pH changes and heat cause denaturation

damages bonds in polypeptide

45

Can denaturation be partial + why

yes if it doesn’t break primary covalent (peptide) bonds but just secondary and tertiary bonds e.g. warm milk

46

Define enzymes

biological catalysts that speed up reactions through providing an alternate pathway for the reaction which requires less energy

47

What is the general suffix of enzymes

ase

48

Examples of enzymes that don’t end in ase

trypsin, pepsin

49

What are the two types of proteins

globular and fibrous

50

What is the solubility of globular/fibrous

globular is soluble and fibrous is insoluble

51

What is the lock and key model

the specific shape of the active site fits exactly the shape of the substrate it will act on, hence will only act on that substrate.

52

What is the induced fit model

the specific shape of the active site of the enzyme varies slightly from that of the substrate and the two fit only after contact when the substrate induces a complementary shape at the active site of the enzyme.

53

Define active site

A region on an enzyme that binds to a protein or other substance during a reaction.

54

Define substrate

The substance on which an enzyme acts.

55

Do enzymes take part in a reaction

no

56

Define coenzyme

organic non-protein molecules required to temporarily and loosely bind with the protein molecule to form an active enzyme.

57

Are coenzymes specific

not always

58

Define hydrolysis

the chemical breakdown of a compound due to the addition of water.

59

What is the general formula for carbohydrates

Cx(H2O)y

60

What elements do carbohydrates contain

C, H, O

61

What is the monomer for sugars

monosaccharides

62

Are carbohydrates soluble and why

due to the multiple -OH groups, they are highly soluble in water because can form H bonding

63

Do all monosaccharides have the same formula

yes (and so are isomers)

64

Can monosaccharides be linear

yes, but most are cyclic

65

What bonds are between sugar molecules

ether/glycosidic links

66

Where does the bond occur between monosaccharides

between the OH groups (and H2O is lost)

67

What polymers are in starch

amylose and amylopectin

68

Is amylose branched or linear

linear

69

Is amylopectin branched or linear

branched

70

What type of isomers are glucose and galactose

stereoisomers

71

What does amylase break starch into

maltose

72

What does maltase break maltose into

glucose

73

What is another name for cellulose

fibre

74

What does GI stand for

glycaemic index

75

What is GI

A figure representing the relative ability of a carbohydrate food to increase the level of glucose in the blood

76

Examples of food high GI

lollies, chocolate, ice-cream

77

Examples of food low GI

brown rice, wholemeal bread, pasta

78

How is glycaemic load calculated

grams in serve * GI /100

79

What is the standard for GI

glucose at 100

80

Why are fruits low GI

because fructose has to be converted to glucose (takes time)

81

What is aspartame

artificial sweetener

82

What are glucose blood levels measured in

mmol-1 (mM)

83

What is called when there is too much blood glucose

hyperglycaemia

84

What is it called when there is too little blood glucose

hypoglycaemia

85

What are the three categories of carbohydrates

monosaccharides, disaccharides, polysaccharides

86

What are the two types of glucose

alpha and beta

87

Where is the OH located on alpha glucose

bottom

88

Where is the OH located on beta glucose

top

89

How many monomers to make polysaccharide

more than 10

90

What are ogliosaccharides

Three to ten monosaccharides bonded together.

91

What is the general suffix for sugars

ose

92

How many times sweeter is aspartame compared to glucose

200 times sweeter

93

Are amylose/amylopectin soluble/insoluble

amylose is soluble and amylopectin is insoluble

94

General formula for glycogen

(C6H12O5)n

95

Properties of glycogen

soluble, highly branched, alpha glucose

96

Properties of starch

slightly soluble, moderately branched, alpha glucose

97

Properties of cellulose

insoluble, unbranched, beta glucose

98

Types of disaccharides (3)

lactose (galactose + glucose), maltose (glucose + glucose), sucrose (glucose + fructose)

99

Types of polysaccharides (3)

starch, cellulose, glycogen

100

What are vitamins

organic compounds that are needed in minute quantities on a regular basis as part of a healthy diet.

101

How many vitamins are required by body

13

102

Can we make vitamins

no, except for Vitamin D

103

Two categories of vitamins

fat soluble and water soluble

104

Examples of fat soluble vitamins

D, A, K, E

105

Examples of water soluble vitamins

B, C

106

Can water soluble vitamins be stored

no

107

Where are fat soluble vitamins stored

in fat (adipose tissue)

108

What is the only non-essential vitamin

Vitamin D

109

What are vitamins needed for

regulating metabolic processes e.g. producing energy, supporting the immune system

110

Are fats solids/liquids

solids

111

Are oils solids/liquids

liquids

112

What enzyme digests fats

lipase

113

What is the formula for a fatty acid with 0 double bonds

CnH2n+1COOH

114

What is the formula for a fatty acid with 1 double bond

CnH2n-1COOH

115

What is the formula for a fatty acid with 2 double bonds

CnH2n-3COOH

116

What are fatty acids

long-chain carboxylic acid containing an even number of carbon atoms.

117

Saturated fatty acid

no double bonds

118

Mono-unsaturated fatty acid

1 double bond

119

Polyunsaturated fatty acid

more than 1 double bond

120

What is the link called in a fatty acid

ester link

121

What are the essential fatty acids of the body

alpha-linolenic acid (ALA) and linoleic acid (LA).

122

What are essential fatty acids also called

omega fatty acids

123

What is omega 3 fatty acid

alpha-linolenic acid

124

What is omega 6 fatty acid

linoleic acid

125

What is the order of energy sources in body

carbohydrates, then fats then proteins

126

Are saturated or unsaturated more likely to go rancid

unsaturated as less stable

127

What is the omega group in fatty acid

methyl

128

What emulsion

breaking down fats (bile)

129

What is calorimetry

Method used to determine the changes in energy of a system by measuring heat exchanges with the surroundings. It is the measurement of the amount of heat released or absorbed in a chemical reaction, change of state or formation of a solution.

130

What is a calorimeter

Apparatus used to measure heat changes during a chemical reaction or change of state.

131

What are different types of calorimeters

bomb calorimeters and solution calorimeters

132

Formula for energy in calorimetry (2)

E = V * I * t or E = n * delta H

133

What is metabolism

chemical processes that involve breaking down and building different substances

134

What is calibration factor

the amount of energy that is required to change the contents of the calorimeter by 1 degree

135

Formula for calibration factor in calorimetry

Cf = E/delta T

136

Unit for calibration factor

J / degrees Celsius

137

Is calories with a lower case c or upper case c

lower case c

138

Is it usually cis or trans in unsaturated fatty acids

cis

139

What is the functional group of monosaccharides

OH

140

What type of double bond (cis or trans) occurs in nature

cis

141

Can trans bonds occur in nature

no