Chapter 1: food and nutrition Flashcards
(368 cards)
1
Q
Factors that affect food choices (9)
A
culture nutritional awareness families lifestyle Finance food availability sensory aspects health status marketing
2
Q
Culture(3)
A
Food traditions of a country
Religious beliefs and values
Travel and immigration
3
Q
Nutritional awareness(3)
A
People are more nutritional conscious due to the work of Bord Bia and the Health Promotion Unit
People check the nutritional labelling of products in order to avoid certain foods
Companies now place specific nutritional information on packaging
4
Q
Families(3)
A
children’s food choices are influenced by watching what their family eats so parents should set a good example
Parents should cook with kids and show them how to read nutritional labels to teach them good nutrition
Children’s food choices depend on what is provided at home, processed foods should be avoided and fresh fruit and veg should be provided
5
Q
Lifestyle(3)
A
Influenced by work, school and activities
A busy lifestyle causes greater reliance on convenience foods as they are quick to cook
A busy lifestyle can also prevent families eating together
6
Q
Finance(3)
A
Families on low incomes may have to choose highly processed foods or may have to opt for cheaper cuts of meat
Families should plan and shop wisely
Greater income families can spend more money on food
7
Q
Food availability(2)
A
Fruit and veg may not be in season so frozen or canned may be used
People in rural places may not have access to the same foods as people living in urban areas
8
Q
Sensory aspect of food choice(3)
A
The senses, especially sight, smell and taste have a major role to play in food choice
Consumers have expectations about the temperature, colour, appearance etc of food often established in childhood
If food doesn’t meet these expectations they will not choose the food
9
Q
Health Status and Food Choices(3)
A
Some people are on restricted diets e.g diabetic
Medical conditions such as heart disease
Food allergies
10
Q
Marketing(1)
A
Marketing strategies e.g sweets at the checkout and advertising on tv influence food choices
11
Q
Classification of minerals (2)
A
Macro minerals-
-required in relatively large amounts e.g calcium. phosphorus, potassium and sodium
Trace minerals-
-required in trace amounts e.g iron, zinc, iodine and flourine
12
Q
Sources of calcium(6)
A
- Milk
- Cheese
- Sardines
- Yogurt
- Leafy green vegetables
- sesame seeds
13
Q
Reference intake of calcium
A
Children/adults
-800mg
Adolescents/Pregnant or lactating women
-1,200mg
14
Q
Functions of calcium (3)
A
- Strong bones and teeth
- Assist blood clotting
- Normal muscle contraction
15
Q
Effects of deficiency (6)
A
- Osteoporosis
- Osteomalacia
- Rickets
- Tooth decay
- Slow blood clotting
- Muscle spasms
16
Q
Factors assisting calcium absorption (5)
A
Vitamin D
-stimulates the production of calcium-binding protein
Parathormone
-a hormone released from the parathyroid gland which controls the levels of calcium in the blood
Oestrogen
-a hormone produced in the ovaries which promotes calcium absorption
Phosphorus
-combines with calcium, creating calcium phosphate which is easier to absorb
An Acid Environment
-an acid environment promotes calcium absorption, consuming foods high in vitamin C provides this
17
Q
Factors hindering calcium absorption (6)
A
Tannins
-found in tea and coffee and bind to calcium inhibiting absorption
Excess dietary fibre
-binds to calcium inhibiting absorption
Excess fat
-binds with calcium, creating insoluble and non-absorbable calcium soaps
Excess protein
-as excess protein is burnt it produces sulphate which increases the amount of calcium excreted in urine
Phytic acid
-found in wholegrain bread and seeds and binds to calcium inhibiting absorption
Oxalic acid
-found in rhubarb and spinach and binds to calcium, inhibiting absorption
18
Q
What three elements make up lipids
A
- hydrogen
- carbon
- oxygen
19
Q
Into what two structures are lipids arranged
A
- Glycerol
- fatty acids
20
Q
How is a lipid made
A
A lipid is made when three fatty acids combine with one glycerol
21
Q
What is the new structure called when a glycerol combines with three fatty acids
A
Triglyceride
22
Q
What is released at each join in a triglyceride
A
Water
23
Q
What is the chemical structure of glycerol (2)
A
Glycerol is a structure with three hydroxyl groups
-refered to as a trihydrate alcohol
H
|
H-C-OH
|
H-C-OH
|
H-C-OH
|
H
24
Q
What is the chemical structure of a fatty acid (3)
A
- A chain of carbons with hydrogens attached
- One end is called the carboxyl end
- The other end is called the methyl end
25
What is the chemical structure of a fat (4)
- A fat is formed when a hydrogen atom from the carboxyl end of a fatty acid joins with the hydroxyl group of a glycerol
- This happens for each of the three fatty acids
- The water is released at each join
- This is a condensation reaction
26
Classify fatty acids (3)
- saturated fatty acids
- monounsaturated fatty acids
- polyunsaturated fatty acids
27
List the characteristics of saturated fatty acid (6)
-Each carbon atom has its full quarter of hydrogens
-There are no double bonds present between the carbon atoms
-They are generally solid at room
-They are generally from animal sources
Contribute to the buildup of cholesterol on the arteries
-High melting points
-Examples include butyric acid in butter and stearic acid in meat
28
List the characteristics of monounsaturated fatty acids(7)
- Each carbon atom has not got it's full quota of hydrogens
- There is one double bond present
- These fatty acids are soft or liquid at room temperature
- The originate from plant sources
- They don't contribute to the buildup of cholesterol on the arteries
- They have a low melting point
- Examples include oleic acid found in olive oil
29
List the characteristics of polyunsaturated fatty acids(7)
- Each carbon atom has not got it's full quota of hydrogen
- There is more than one double bond
- These fatty acids are soft or liquid at room temperature
- They originated from plant or marine sources
- They do not contribute to the buildup of cholesterol on the arteries
- They have a low melting point
- Examples include linoleic acid found in corn oil linolenic acid in vegetable oil and seeds and arachidonic acid found in oily fish
30
What are essential fatty acids (2)
These cannot be manufactured in the body and must be supplied by the diet
Examples include linoleic acid in corn oil
31
List the functions of the essential fatty acids(4)
- Build cell membranes
- Counteract the hardening effect of cholesterol on the arteries
- Helps prevent coronary heart disease as they raise raise hdl cholesterol in the blood
- Sources include nuts, seeds and fatty acids
32
List the characteristics of Omega-3 fatty acids (4)
- They are polyunsaturated fatty acids
- Omega-3 related to the positioning of the double bond
- The double bond is between the third and fourth carbon counting from the methyl end
- Sources include oily fish, salmon, herring, mackerel, nuts, soya beans, supplements
33
Benefits of Omega-3 fatty acids(3)
- reduces the risk of heart attack, stroke, circulatory diseases and formation of blood clots
- increases hdl cholesterol levels
- it is also associated with healthy brain activity and fetal brain development
34
What are cis and trans fatty acids
Cis and trans fatty acids are based on the position of the hydrogen atoms at the double bond of an unsaturated fatty acid
35
Describe cis fatty acids(3)
- Cis fatty acids occur when the hydrogen atoms on either side of the double bond are both above or below the carbons
- All naturally occurring unsaturated fatty acids are cis fatty acids
- Cis fatty acids do not cause cholesterol to build up on the arteries
36
Describe trans fatty acids (4)
- Trans fatty acids occur when the hydrogen atoms on each side of the double bond are on opposite sides
- This structure makes them behave like a saturated fatty acid
- They don't occur naturally but are formed from cis fatty acids when they are heated and during processing of cis fatty acids
- Tests have shown that they raise the level of the LDL lipoproteins and reduce HDL or good cholesterol
37
Functions of fats(5)
- Heat and energy
- Protection of delicate organs
- Provision of the fat soluble vitamins A,D,E and K
- Essential fatty acids- formation of cell membranes and counteracts the hardening effects of cholesterol on the arteries
- Omega 3-improves brain activity, prevents certain cancers, prevents against coronary heart disease and strokes etc
38
Ill effects of fats (3)
- Excess fat is stored as far which can lead to obesity
- Excess fat can inhibit calcium absorption leading to osteoporosis
- Blocks arteries which can lead to heart attack, stroke or coronary heart disease
39
Properties of lipids - Solubility (2)
- Lipids are insoluble in water
| - Lipids are soluble in solvent e.g ether or benzene
40
Properties of lipids - hydrogenation (3)
- The process of forcing hydrogen through the double bond of an unsaturated fatty acids (nickel catalyst)
- The unsaturated fat now becomes saturated (liquid to solid)
- This property is evident in the production of margarine (culinary application)
41
Properties of lipids- plasticity (2)
- Lipids can have properties of both a solid(saturated) and a liquid(unsaturated) fat.
- Margarine is used in the creaming method as it has shape and structure but are soft and spreadable
42
Properties of lipids (affected by heat) (melting point) (2)
- Solids melt when heated
| - Fats melt at 30-40°C
43
Properties of lipids (affected by heat)(smoke point)(5)
- Lipids begin to decompose and the glycerol separates from the three fatty acids
- A blue haze emerges
- An acrid smelling compound known as acrolein is present
- Fats reach smoke point at 200°C
- Oils reach smoke point at 250°C
44
Properties of lipids (affected by heat)(flash point)(4)
- The decomposition of the lipids continues
- Lipids spontaneously burst into flames
- Fats reach flash point at 310°C
- Oils reach flashpoint at 325°C
45
Properties of lipids (rancidity) (6)
- This is the term used to describe lipids when they "go off" (results in an unplreasant odour and taste)
- There are two types of rancidity (oxidative and hydrolytic)
- To prevent rancidity, store food correctly (fats in the fridge and oils in a cool dark place) and manufacturers of fatty foods use an anti-oxidant
- Anti-oxidants occur naturally in vitamins A,C and E and artificially in BHA and BHT
- Anti-oxidants are widely used in the food industry to prolong shelf life
- They are found in foods like biscuits, cooking fats, dairy spreads, stock cubes and oil
46
Oxidative rancidity (3)
- This form of rancidity occurs when oxygen is forced through the double bond of an unsaturated fatty acid
- It is the most common form of rancidity
- Examples include oil solidifying on a pan
47
Hydrolytic rancidity (4)
- This form of rancidity occurs when enzymes and bacteria react with the lipid
- It results in the triglycerides breaking down(glycerol separates from the fatty acids)-flavour is altered
- This occurs most commonly in freezers when enzymes are not destroyed
- Occurs in both saturated and unsaturated fats
48
Properties of lipids (emulsions) (3)
- When two immiscible liquids are forced together, an emulsion is formed
- The emulsion can either be permanent or temporary
- There are two types of emulsions: oil in water e.g. milk and water in oil e.g butter
49
A permanent emulsion (1)
Occurs when oil and water are forced together permanently in the presence an emulsifier, e.g. mayonnaise (oil and vinegar and emulsifier (lecithin in egg yolk equals an emulsion)
50
A temporary emulsion (1)
Occurs when oil and vinegar are forced together, e.g. french dressing - this is caused by shaking and will separate again when standing
51
Emulsifiers (3)
- An emulsifier has two parts: a water loving head (hydrophilic) and a water hating tail (hydrophobic)
- The hydrophilic head attaches to water/vinegar while the hydrophobic tail attaches to the oil
- The oil and vinegar/water will not separate
52
Culinary application of emulsifiers (5)
- The making of mayonnaise
- Mayonnaise is made from oil and vinegar which don't mix
- An egg yolk is added in because it contains lecithin a natural emulsifier
- The vinegar sticks to the head and the oil sticks to the tail
- As a result they don't separate
53
Digestion of lipids- what happens in the mouth (1)
-Food is chewed
54
Digestion of lipids- what happens in the stomach (1)
-The heat of the stomach melts the fats which increases the surface area for digestion
55
Digestion of lipids- Duodenum (2)
- This contains bile from the liver which emulsifies the fats
- It also contains pancreatic juice from the pancreas which contains an enzyme called lipase. This lipase starts to break fats into fatty acids and glycerol
56
Digestion of fats- Ileum (1)
- Contains intestinal juices which also contain lipase which finishes the breakdown of fats into fatty acids and glycerol
57
Absorption of lipids(4)
- The fatty acids and glycerol pass through the walls of the villi
- From here they pass into the lymph system
- The fatty acids and glycerol are then carried in the lymph up as far as the neck and are then deposited into the blood stream up at the left side of the neck in the subclavian vein
- The blood now brings the digested fat back to the liver
58
Utilisation of lipids- oxidisation in the liver and muscles (2)
- In the liver and muscles lipids are oxidised to;
- produce heat and energy
- form cell membranes
59
Utilisation of lipids- storage of excess fat in the adipose tissue under the skin
- Excess fat is removed out of the liver and is stored as adipose tissue underneath the skin, this;
- insulates the body
- acts as an energy reserve
- protects the delicate organs
60
What are proteins made up of?
| 2
- they are made up of amino acids
| - joined together
61
How many amino acids are there?
| 1
-twenty
62
What four main elements make up an amino acid?
| 4
- carbon
- hydrogen
- oxygen
- nitrogen
63
What three elements are only sometimes found in amino acids?
| 3
- iron
- phosphorus
- sulphur
64
What is the structure of an amino acid?
| 6
- a carbon(C)
- connected to a
- hydrogen(H)
- amino end (NH2)
- carboxyl end (COOH)
- and a variable (R)
65
What is the structure of the amino acid glycine?
| 6
- a carbon(C)
- connected to
- hydrogen (H)
- amino end (NH2)
- carboxyl end (COOH)
- and a second hydrogen (H)
66
What are essential amino acids?
| 5
- these are amino acids
- that cannot be made naturally by the body
- they have to be obtained by food
- foods which provide them are called high biological value foods
- there are eight essential amino acids
67
What are non-essential amino acids?
| 3
- these are amino acids that the body can make
- they do not have to be obtained from food
- there are twelve of them
68
List the essential amino acids
| 8
- Valine
- Lysine
- Leucine
- Isoleucine
- Phenylalanine
- Methionine
- Threonine
- Tryptophan
69
List the non essential amino acids?
| 12
- Alanine
- Aspartic acid
- Cysteine
- Ornithine
- Serine
- Asparagine
- Proline
- Tyrosine
- Glycine
- Glutamic acid
70
What are the structural functions of proteins?
| 6
- production of cell membranes,
- muscle tissue
- and skin
- cell repair
- and replacement
- growth
71
What are the physiologically active functions of proteins?
| 5
- hormonal proteins: help to coordinate bodily activities e.g. production of insulin
- enzymes: speed up chemical reactions, e.g. pepsin speeds up the breakdown of proteins into food
- antibodies (Immunoglobulins): defend the body from harmful substances, e.g. viruses
- blood proteins: move molecules around the body e.g. haemoglobin transports oxygen through the blood
- nucleoproteins (DNA): make up the hereditary material in chromosomes
72
What are the nutrient factors of proteins?
- provide the body with essential amino acids
| - excess can be used as a source of energy when carbohydrate and fat reserves are used
73
How is a protein formed?
| 6
- proteins are formed when two or more amino acids join together
- this join is called a peptide bond
- a water is lost at each join
- the carboxyl end of one amino acid joins with the amino end of the next with the loss of a water
- the carboxyl end loses an OH where as the NH2 amino end loses a H
- the resulting bond(the peptide bond) is CONH
74
Explain the primary structure of a protein
| 3
- this is the number and sequence of amino acids in the polypeptide chain
- each of these are held together by a peptide bond(next you explain how a peptide bond is formed)
- e.g. insulin has 51 amino acids
75
Explain the secondary structure of a protein
| 4
- this is the further linking of the polypeptide chain with extra bonds or links
- it gives the protein a definite 2 dimensional shape (normally spiral)
- the links are called cross links or cross bonds
- two specific examples of cross bonds are disulfide bonds and hydrogen bonds
76
Explain a disulfide bond of a protein
| 4
- this is where two amino acids containing the elements sulphur link together
- an example of an amino acid that contains sulphur is cystine
- the two sulphurs in the two cystines link together with a bond called a disulphide bond
- as a result of these disulphide links the chain coils into a two dimensional spiral shape
77
Explain a hydrogen bond in a protein
| 3
- these bonds occur when a hydrogen from one amino acid joins with an oxygen of another amino acid
- this can occur on the one chain or between two neighbouring chains
- a spiral shaped protein also results
78
Explain a tertiary bond in a protein
| 5
- this is the further folding and linking of the secondary structure
- to give the protein a three dimensional shape
- (normally fibrous or globular)
- more cross links form to hold it in place
- it is only now that it starts to function as a protein
79
Deficiencies associated with protein
| 5
- retarded growth
- delayed healing of wounds
- susceptibility to disease and infection
- lack of energy
- kwashiorkor and marasmus in severe cases
80
Classification of proteins
| 2
- simple proteins
| - conjugated proteins
81
What are simple proteins
| 2
- these consist of only amino acids along the chain
| - they can be further broken down into amino and plant proteins
82
What are the two groups of simple proteins
| 2
- animals
| - plant
83
What are the animal simple protein subgroups
| 2
- fibrous
| - globular
84
What are the plant simple protein subgroups
| 2
- glutenins
| - prolamines
85
What are examples of fibrous simple proteins
| 2
- elastin
| - collagen
86
What is a source of the fibrous simple protein elastin
| 1
-meat connective tissue
87
What is a source of the fibrous simple protein collagen
| 1
-meat connective tissue
88
What are examples of globular simple proteins
| 2
- ovalbumin
| - lactalbumin
89
What are sources of the globular simple protein ovalbumin
| 1
-egg whites
90
What are sources of the globular simple protein lactalbumin
| 1
-milk
91
What are examples of glutenin simple proteins
| 2
- glutenin
| - oryzenin
92
What are examples of prolamine simple proteins?
| 2
- gliadin
| - zein
93
What are sources of the glutenin simple protein?
| 1
-wheat
94
What are sources of the oryzenin simple protein?
| 1
-rice
95
What are sources of gliadin the simple protein?
| 1
-wheat
96
What are sources of zein the simple protein?
| 1
-maize
97
What are conjugated proteins?
| 2
-somewhere along the chain of amino acids -there is a non protein molecule attached
98
What are lipoproteins?
| 1
-chain of amino acids with a lipid attached
99
What is an example of a lipoprotein?
| 1
-lecithin is a protein found in egg but it has fat present too
100
Explain the denaturation property of proteins.
| 5
-it is a change in the nature of a protein
-it causes the protein chain to unfold
-which leads to an irreversible loss in structure
-over this happens the protein often sets or becomes hard (coagulation)
-it is caused by;
Heat
Agitation
Chemicals
101
Explain how heat causes the denaturation of a protein
| 2
- causes the protein to harden and set
| - e.g eggs
102
Explain how agitation causes the denaturation of a protein.
| 2
- whipping a protein food brings about partial coagulation
| - e.g. an egg white becomes foam
103
Explain how chemicals cause the denaturation of a protein
| 2
- such as acids, alkalis and enzymes cause change in protein structure
- e.g. addition of lemon juice to eggs cause it to coagulate
104
What are the culinary applications of the denaturation property of proteins?
(1)
-useful in the making of sponges and quiches
105
Explain the mallard reaction property of proteins.
| 3
- this is the non-enzymic browning of protein foods
- it occurs when an amino acid reacts with a carbohydrate
- under dry heat
106
What are the culinary applications of the mallard reaction property of proteins.
(2)
- it gives a nice brown colour
| - to roast potatoes, roast meat and shortbread biscuits
107
Explain the gel formation property of proteins
| 4
- a gel is a semi-solid, viscous solution in which water molecules are trapped
- gelatine is made from the protein collagen and it can absorb large amounts of water to form a gel
- if this is heated it forms a sol and on cooling the sol becomes semi-solid
- this process is called gel formation
108
What are the culinary applications of the gel formation property of proteins?
(1)
-the setting powder is used in making cheesecakes and souflees and jellies
109
Explain the foam formation property of proteins
| 4
- when an egg white is whisked the 3-D protein structure unfolds(denatures)
- air bubbles become trapped within the unfolded chains creating a foam
- the whisking action also generates a little heat which sets the egg white slightly (temporary foam)
- to hold it in this state it needs to be put into an oven
110
What are the culinary applications of the foam formation property of proteins?
(1)
-the making of meringues
111
Explain the elasticity property of proteins
| 1
-some fibrous proteins e.g. gluten in wheat, are quite elastic
112
What are the culinary properties of the elasticity property of proteins?
(1)
-gluten makes yeast dough elastic enough to trap the CO2 gas produced by yeast, helping it to rise
113
Explain the solubility property of proteins
| 3
- most proteins are insoluble in water,
- apart from collagen in meat (soluble in hot water)
- and egg albumin (soluble in cold water)
114
What are the culinary applications of the solubility property of proteins?
(1)
-moist heat tenderises meat by converting collagen to elastin
115
What is the biological value of a protein?
| 4
-it is the measure of the quality of protein
-it is expressed as a percentage
-it is determined by the number of essential amino acids present in the food
-there are two groups;
high
low
116
What is a high biological value protein?
| 4
- contains nearly all the essential amino acids in the correct proportions
- e.g. eggs have 100 percent
- also known as complete proteins
- generally come from animal sources but also the soya bean
117
What is a low biological value protein?
| 4
- contains only some of the essential amino acids
- also known as incomplete proteins
- come from plant sources but also gelatine
- e.g. rice has 67 percent
118
What is complementary rate/ supplementary value?
| 6
- consuming two LBV protein foods together, each different essential amino acids are obtained
- e.g. beans and toast
- beans are low in methionine and high in lysine
- toast is low in lysine and high in methionine
- by eating beans and toast together all essential amino acids are got
- useful in the diet of vegetarians
119
Describe the breakdown of proteins during digestion
| 4
- protein to
- peptones to
- peptides to
- amino acids
120
How are proteins broken down in the stomach?
| 4
- the secretion of gastric juice
- which contains the enzymes rennin and pepsin
- act on caeseinogen proteins(substrate)
- to make casein peptones
121
How are proteins broken down in the pancreas?
| 4
- pancreatic juice is secreted into the duodenum
- along with the enzyme trypsin
- act on peptones(substrate)
- to make peptides
122
How are proteins broken down in the small intestine (ileum)?
| 4
- the secretion of intestinal juice
- along with the enzyme peptidase(erypsin)
- act on the substrate peptides
- to make amino acids
123
What are hormonal proteins?
| 2
- these help to coordinate bodily activities
| - e.g. production of insulin
124
What are enzymes?
| 2
- these speed up a chemical reaction
| - e.g. pepsin speeds up the breakdown of proteins in food
125
What are antibodies?
| 3
- also called immunoglobulins
- they defend the body from harmful substances
- e.g. viruses
126
What are blood proteins?
| 2
- these move molecules around the body
| - e.g. haemoglobin transports oxygen through the blood
127
What are nucleoproteins
| 2
- also called DNA
| - these make up the heredity material in chromosome
128
What are the effects of dry heat on proteins?
| 2
- maillard reaction
| - e.g. roast beef
129
What are the effects of moist heat on proteins?
| 4
Tenderising Meat
- collagen in meat converts to gelatine
- causing the fibres to tenderise
- e.g. pulled pork
130
What are the effects of both dry and moist heat on protein?
| 3
Coagulation:
-e.g. egg whites coagulate at 60 degrees Celsius and egg yolks at 68 degrees Celsius
Colour Change:
-e.g. myoglobin (red pigment) in meat changes to haematin (brown pigment)
Overcooking:
-causes proteins to become indigestible
131
Describe the absorption and utilisation of amino acids
| 5
- amino acids pass through the walls of the villi
- the villi past them into the portal vein and are brought to the liver
- in the liver they are used to maintain and repair liver cells
- summer released back into the bloodstream again and they brought around the body to form new cells, repair damaged cells and manufacture hormones enzymes antibodies in DNA
- the excess is deaminated to produce heat and energy
132
Describe protein deamination
| 4
- the breakdown of excess protein in the body and using it as a source of energy
- 16 occur in the liver
- the amino end is removed from the amino acid and is changed into ammonia and then into urea and is excreted by kidneys as urine
- the carboxyl end is removed and oxidized to produce heat and energy
133
Classify Vitamins
| 2
- fat soluble vitamins
| - water soluble vitamins
134
What are fat-soluble vitamins?
| 2
- normally found in food that contains fat
| - can be stored in the liver for several months
135
List the fat-soluble vitamins
| 4
- vitamin A
- vitamin D
- vitamin E
- vitamin K
136
What are water-soluble vitamins?
| 3
- found in a wide variety of foods
- not stored in the body
- the excess is excreted
137
List the water soluble vitamins
| 2
- vitamin C
| - B group vitamins
138
What are the two forms of vitamin A?
| 2
- retinol (pure vitamin A)
| - beta-carotene (pro-vitamin A)
139
What is retinol (pure vitamin A)?
| 2
- easily absorbed
| - stored in the liver
140
What is beta-carotene (pro-vitamin A)?
| 2
- not easily absorbed
| - converted to retinol in the lining of the intestine
141
What are the properties of retinol (pure vitamin A)?
| 5
- a yellow, fat-soluble alcohol
- insoluble in water
- soluble in organic solvents, e.g. acetone
- heat stable, but affected by prolonged high temperatures
- destroyed by oxygen
142
What are the properties of beta-carotene (pro-vitamin A)?
| 6
- a yellow or orange fat-soluble oil
- insoluble in water
- soluble in fat solvents, e.g. alcohol
- heat stable, but affected by prolonged high temperatures
- unaffected by oxygen
- a powerful antioxidant which counteracts the damaging effects of free radicals and can prevent certain cancers, aging of the skin and heart disease
143
List some sources of retinol (pure vitamin A)
| 8
- fish liver oils
- milk
- eggs
- butter
- offal
- cheese
- margarine
- oily fish
144
List some sources of beta-carotene (pro-vitamin A)
| 6
- carrots
- tomatoes
- red peppers
- leafy green vegetables
- apricots
- sweet potatoes
145
What food sources provide retinol (pure vitamin A)?
| 1
-found in animal food sources
146
What food sources provide beta-carotene (pro-vitamin A)
| 2
- found in yellow, green and orange fruit and vegetables
| - carotenoids
147
List the functions of vitamin A
| 5
- manufactures the pigment rhodopsin
- healthy skin and mucous membranes
- healthy skin and hair
- aids growth and development of children
- powerful antioxidant
148
Describe the importance of vitamin A and the production of rhodopsin
(3)
- it is required to manufacture the pigment rhodopsin
- pigment found in the retina
- helps the eye adapt to dim light
149
Describe the importance of vitamin A and the maintaining of healthy skin and mucous membranes
(3)
- it is required to maintain healthy skin and the mucous membranes of the body
- e.g. the eyes/nose/throat
- prevents infection
150
Describe the importance of vitamin A and the effect of antioxidants
(3)
- beta-carotene acts as a powerful antioxidant
- it counteracts the damaging effects of free radicals
- it can prevent certain cancers, aging of the skin and heart disease
151
List the effects of deficiency of vitamin A
| 5
- night blindness
- follicular hyperkeratosis
- xerophthalmia
- stunted or delayed growth
- damage to cells by free radicals
152
Describe how a deficiency of vitamin A causes night blindness
(2)
- night blindness, whereby a person will struggle to see in dim light
- due to a lack of rhodopsin
153
Describe follicular hyperkeratosis caused by a deficiency of vitamin A
(1)
-this causes rough, dry skin and inflamed hair follicles
154
Describe xerophthalmia caused by a deficiency in vitamin A
| 4
- occurs on the surface of the eyes
- due to a lack of mucous
- causes eyes to dry out and become infected with bacteria
- can eventually lead to blindness
155
Describe stunted or delayed growth caused by a deficiency in vitamin A
(2)
- stunted or delayed growth in children
| - leaving them smaller in height than the average for their age
156
Describe how damage to cells by free radicals is caused by a deficiency in vitamin A
(2)
- risk of damage to cells by free radicals
| - increasing the risk in some cancers coronary heart disease and strokes
157
What is the RI of vitamin A for children?
| 1
-400-500µg
158
What is the RI of vitamin A for adolescents and adults?
| 1
-600-700µg
159
What is the RI of vitamin A for pregnant women?
| 1
-700µg
160
What is the RI of vitamin A for lactating women?
| 1
-950µg
161
What is the other name for vitamin D?
| 1
-calciferol
162
What are the two forms of vitamin D?
| 2
- cholecalciferol D3
| - ergocalciferol D2
163
Describe what the cholecalciferol D3 form of vitamin D is.
| 3
- an animal form of vitamin D
- created when UV light shines on the skin
- converts 7-dehydrocholesterol in the epidermis to cholecalciferol
164
Describe what the ergocalciferol D2 form of vitamin D is.
| 4
- a plant form of vitamin D
- created when UV light shines on fungi and yeasts
- converts ergosterol into ergocalciferol
- used in vitamin supplements
165
What are the properties of vitamin D?
| 7
- the most stable of all the vitamins
- fat soluble
- insoluble in water
- heat stable: unaffected by cooking or preservation methods
- unaffected by acids
- unaffected by alkalis
- unaffected by oxygen
166
List some food sources of vitamin D
| 6
- oily fish
- fortified milk
- margarine
- eggs
- fish liver oils
- butter
167
What is a source of vitamin D other then food?
-sunlight
168
How much sunlight do humans need to produce enough vitamin D per day?
-20 minutes per day
169
List the functions of vitamin D.
| 3
- absorption of calcium and phosphorus
- regulates the amount of calcium and phosphorus in the bones and teeth
- regulates calcium levels in the blood
170
Describe where vitamin D controls the absorption of calcium and phosphorus
(1).
-controls the absorption of calcium and phosphorus into the blood
171
Describe the effect of vitamin D regulating the amount of calcium and phosphorus in the bones and teeth.
(1)
-regulates the amount of calcium and phosphorus in the bones and teeth, helping to maintain density and strength
172
Describe how vitamin D regulates calcium levels in the blood
| 1
-if blood-calcium levels are too low, it stimulates the production of a calcium-binding protein needed to absorb more calcium
173
List the effects of deficiency of vitamin D
| 4
- rickets
- osteomalacia
- osteoporosis
- tooth decay
174
Explain what is rickets caused by a deficiency of vitamin D.
| 2
- a bone disease that affects children, causing their bones to become soft and weak
- this can lead to an increased risk of fractures and bone deformities, e.g. bow legs
175
Explain what is osteomalacia caused by a deficiency of vitamin D
(2)
- a bone disease that affects adults, causing their bones to become soft and weak due to low bone mass
- this can lead to an increased risk of fractures and bone pain
176
Explain what is osteoporosis caused by a deficiency of vitamin D
(2)
- a bone disease common in older people or post-menopausal women, causing their bones to become brittle and fragile due to a loss of bone mass
- this can lead to an increased risk of fractures, stopped posture and back pain caused by a collapsed vertebra
177
Explain what is tooth decay caused by a deficiency of vitamin D
(1)
-a condition where the tooth enamel, bone and cementum weaken, increasing the risk of dental decay
178
What is hypervitaminosis?
(NOTES COPY)
179
What are the symptoms of hypervitaminosis A?
| 4
- miscarriage
- bone pain
- birth defects
- enlarged liver
180
What are the symptoms of hypervitaminosis D?
| 4
- vomiting
- weight loss
- kidney damage
- can lead to death
181
What is another name for vitamin E?
| 1
-tocopherol
182
What are the properties of vitamin E?
| 9
- fat soluble
- insoluble in water
- unstable to alkalis
- unstable to light
- antioxidant
- unaffected by acids
- unaffected by oxygen
- unaffected by UV light
- heat stable even at high temperatures
183
List some sources of vitamin E.
| 6
- nuts
- wheat germ
- seeds
- avocados
- vegetable oils
- eggs
184
List the functions of vitamin E
| 8
- strengthens the immune system
- has been linked to reducing the onset of Alzheimer's
- decreases symptoms of pre-menstrual syndrome
- powerful antioxidant
- improves blood clotting
- protects red and white blood cells from damage
- aids the development of the retina
- protects the retina in the eyes of newborn babies
185
Explain the function of the antioxidant property of vitamin E.
(1)
-counteracts the damaging effects of free radicals
186
List the effects of deficiency of vitamin E
| 5
- quite rare as it is available in most foods
- damage to cells by free radicals
- anaemia
- reduced immunity
- eye disorders
187
Describe the effect of free radicals due to a lack of vitamin E
(1)
-risk of damage to cells by free radicals, increasing the risk of some cancers, coronary heart disease and strokes
188
Describe how anaemia is caused by a deficiency of vitamin E.
| 1
-due to low levels of red blood cells, which are needed to transport oxygen
189
Describe how reduced immunity is caused by a deficiency of vitamin E
(1)
-due to low levels of white blood cells which are needed to fight infection
190
Describe the eye disorders that are a result of a deficiency of vitamin E
(1)
-eye disorders in premature babies, which can lead to blindness
191
What is another name for vitamin K?
| 1
-naphthoquinones
192
What are the three forms of vitamin K?
| 3
- phylloquinone K1
- menaquinone K2
- menadione K3
193
Where is the phylloquinone K1 form of vitamin K made?
| 1
-made by plants
194
Where is the menaquinone K2 form of vitamin K made?
| 1
-made by intestinal bacteria
195
Where is the menadione K3 form of vitamin K made?
| 1
-a synthetic form (tablets)
196
What are the properties of vitamin K?
| 6
- fat soluble
- insoluble in water
- destroyed by oxygen
- destroyed by light
- heat stable
- stable in acidic conditions
197
List some food sources of vitamin K.
| 5
- leafy green vegetables
- offal
- oily fish
- cereals
- fish liver oils
198
Name a non-food source of vitamin K.
| 1
-synthesised by bacteria in the small intestine
199
List the functions of vitamin K.
| 5
- clotting of blood
- regulates the level of calcium in bones
- helps prevent bone diseases
- helps reduce cardiovascular diseases
- helps reduce varicose veins
200
Describe how vitamin K aids the clotting of blood
| 2
- aids the clotting of blood by synthesising prothrombin
| - a chemical needed in the blood to clot
201
List the effects of a deficiency of vitamin K
| 2
- slow blood clotting
| - risk of bone conditions
202
Describe slow blood clotting as a result of a vitamin k deficiency
(2)
- slow blood clotting of ruptured blood vessels, leading to haemorrhaging
- this is common in newborn babies, as their diet lacks vitamin k and their intestines may not have begun to produce it
203
Describe the increased risk of bone conditions caused by a deficiency of vitamin k
(1)
-increased risk of bone fractures and bone disease such as osteoporosis
204
What is another name for vitamin C?
| 1
-ascorbic acid
205
What are the properties of vitamin C?
| 10
- most unstable of all the vitamins
- insoluble in fat
- water soluble
- antioxidant
- acid with a sharp or sour taste
- destroyed by heat
- destroyed by alkalis
- destroyed by light
- destroyed by oxidase
- destroyed by metals
206
What is oxidase?
| 1
-an enzyme present in the cell walls of fruit and vegetables
207
What are some sources of vitamin C?
| 8
- blackcurrants
- oranges
- lemons
- strawberries
- tomatoes
- peppers
- broccoli
- cabbage
208
List the functions of vitamin C
| 7
- forms healthy gums and prevents inflammation
- absorption of calcium
- forms tissues
- absorption of iron
- maintains the immune system
- powerful antioxidant
- promotes quick wound-healing
209
Describe how vitamin C forms tissue
| 3
- forms collagen
- which helps to hold cells together to form tissue
- e.g. skin or blood vessels
210
Describe how vitamin C assists with the absorption of iron.
| 1
-it chemically changes ferric iron (non-haem) to ferrous iron (haem)
211
Describe how vitamin C maintains the immune system.
| 1
-by helping white blood cells to fight illness and infection
212
Describe the effect vitamin C has as being an antioxidant.
| 1
-can counteract the damaging effects of free radicals
213
List the effects of deficiency of vitamin C
| 7
- scurvy
- weakened body tissue
- wounds take longer to heal
- increased risk of infection
- anaemia
- increased susceptibility to illness and infection
- damage to cells by free radicals
214
Describe what is scurvy caused by a deficiency in vitamin C
| 3
- a severe gum disease
- symptoms include inflamed or receding gums
- causes teeth to become loose and fall out and haemorrhaging under the skin
215
Describe the effects of weakened body tissues caused by a deficiency of vitamin C
(1)
-causes blood vessels to rupture easily which lead to bruising and bleeding
216
Describe anaemia caused by a deficiency of vitamin C
| 1
-may occur due to reduced absorption of iron needed to make haemoglobin
217
Describe the damage to cells caused by free radicals as a result of a deficiency of vitamin C
(1)
-risk of damage to cells by free radicals, increasing the risk of some cancers, coronary heart disease and strokes
218
What is the recommended daily allowance of vitamin C for children?
(1)
-45mg
219
What is the recommended daily allowance of vitamin C for adolescents?
(1)
-50-60mg
220
What is the recommended daily allowance of vitamin C for adults?
(1)
-60mg
221
What is the recommended daily allowance of vitamin C for pregnant or lactating women?
(1)
-80mg
222
What is another name for vitamin B12?
| 1
-cobalamin
223
List the properties of cobalamin.
| 6
- water soluble
- insoluble in fat
- destroyed by strong acids
- destroyed by alkalis
- destroyed by light
- heat stable up to 100 degrees, but some loss during cooking
224
List food sources of cobalamin
| 4
- offal
- eggs
- milk
- meat
225
List a source of cobalamin other than food
| 1
-vegans are strongly advised to take supplements or to consume fortifies foods e.g. soya milk
226
List the functions of cobalamin
| 4
- metabolism of fatty acids to release energy
- aids the metabolism of folate/folic acid
- maintains the myelin sheath which speeds up nerve impulses
- aids the formation of red blood cells
227
What is the myelin sheath
| 1
-a protective layer that surrounds the nerve fibres of the nervous system
228
List the effects of deficiency of cobalamin
| 4
- tiredness and irritability due to a lack of energy
- increased risk of neural tube defects in the foetus
- delayed nerve impulses
- pernicious anaemia
229
Describe what delayed nerve impulses due to a deficiency of cobalamin causes
(2)
- leads to cognitive impairment
| - e.g. memory loss or slow mental response
230
How does a deficiency of cobalamin cause pernicious anaemia?
| 1
-due to low levels of red blood cells that are needed to transport oxygen
231
What is the recommended daily allowance of cobalamin for children?
(1)
-0.7-1 micrograms
232
What is the recommended daily allowance of cobalamin for adolescents and adults?
(1)
-1.4 micrograms
233
What is the recommended daily allowance of cobalamin for pregnant women?
(1)
-1.6 microgram
234
What is the recommended daily allowance of cobalamin for lactating women?
(1)
-1.9 micrograms
235
What form is folate found in?
| 1
-a natural form found in food
236
What form is folic acid in?
| 1
-a synthetic form used to make supplements
237
What are the properties of folate/folic acid?
| 7
- water soluble
- insoluble in fat
- heat stable, but some lost during cooking
- unaffected by acids
- destroyed by alkalis
- destroyed by oxygen
- destroyed by light
238
What are some food sources of folate/folic acid?
| 5
- leafy green vegetables
- wheat germ
- wholemeal bread
- offal
- fortified breakfast cereals
239
What is another source of folate/folic acid other then food?
| 1
-in pregnancy women are advised to take daily folic acid supplements for 12 weeks prior to conception and 12 weeks after
240
List the functions of folate/folic acid
| 5
- formation of a foetus
- genetic material in a foetus
- metabolises protein
- works with cobalamin to from red blood cells
- maintains the immune system
241
Describe what folate/folic acid forms in a foetus
| 2
- forms the brain of a foetus
| - closes the end of its spinal cord
242
Describe the genetic material that is formed by folate/folic acid
(1)
-essential for the manufacture of genetic material such as DNA and RNA during pregnancy
243
Explain how folate/folic acid maintains the immune system
| 1
-helps the white blood cells to fight illness and infection
244
List the effects of a deficiency of folate/folic acid.
| 4
- spina bifida
- anencephaly
- tiredness and fatigue
- increased susceptibility to illness and infection such as colds and flu
245
Describe spina bifida caused by a deficiency of folate/folic acid.
(3)
- a neural tube defect
- occurs when the base of the spine fails to close
- causing paralysis of the lower limbs
246
Describe anencephaly caused by a deficiency of folate/folic acid
(3)
- a neural tube defect
- occurs when the top of the spine fails to close, and the brain, skull and scalp do not develop
- a baby with this condition is not likely to survive
247
How does a deficiency of folate/folic acid cause tiredness and fatigue?
(2)
- mild cases of deficiency will lead to feelings of tiredness or fatigue due to a lack of red blood cells
- in severe cases anaemia may occur
248
What is the recommended daily allowance of folate/folic acid for children?
(1)
-100-200 micrograms
249
What is the recommended daily allowance of folate/folic acid for adolescents and adults?
(1)
-300 micrograms
250
What is the recommended daily allowance of folate/folic acid for pregnant women?
(1)
-500 micrograms
251
What is the recommended daily allowance of folate/folic acid for lactating women?
(1)
-400 micrograms
252
What is another name for vitamin B1?
| 1
-thiamine
253
What are the properties of thiamine?
| 6
- water soluble
- insoluble in fat
- destroyed by high temperatures
- destroyed by alkalis
- destroyed by light
- 70% is lost during milling
254
List some food sources of thiamine
| 4
- meat
- milk
- offal
- eggs
255
What is another source of thiamine other then food?
| 1
-a small amount is synthesised by bacteria in the large intestine
256
List the functions of thiamine
| 5
- aids metabolism of carbohydrates to release energy
- aids the metabolism of fat to release energy
- aids the correct functioning and maintenance of nerves
- makes hydrochloric acid in the stomach
- aids the growth and development of children
257
List the effects of a deficiency of thiamine
| 3
- tiredness and irritability due to a lack of energy
- beri beri
- stunted or delayed growth in children
258
Describe what is beri beri caused by a deficiency of thiamine
(3)
- severe deficiency can result in beri beri,
- a serious nerve disease
- causes muscular pain, paralysis and death
259
Describe the result of stunted or delayed growth in children due to a deficiency of thiamine
(1)
-leaves children smaller in height than the average for their age
260
What is another name for vitamin B2?
| 1
-riboflavin
261
What are the properties of riboflavin?
| 5
- water soluble
- insoluble in fat
- unstable at high temperatures
- destroyed by alkalis
- sensitive to light
262
What are some food sources of riboflavin?
| 4
- meat
- offal
- milk
- eggs
263
List the functions of riboflavin
| 6
- aids the metabolism of carbohydrates to release energy
- aids the metabolism of proteins to release energy
- aids the metabolism of fat to release energy
- maintains healthy mucous membranes of the body e.g. eyes and mouth
- aids growth and development of children
- healthy hair, skin and eyes
264
List the effects of a deficiency of riboflavin
| 6
- tiredness and irritability due to a lack of energy
- a swollen, red tongue
- sore cracked lips
- dry eyes
- stunted or delayed growth in children
- dermatitis and skin rashes
265
Describe the effect of stunted or delayed growth in children due to a deficiency of riboflavin
(1)
-leaves children smaller in height than the average for their age
266
What is another name for vitamin B3?
| 1
-niacin
267
What are the properties of niacin?
| 6
- water soluble
- insoluble in fat
- stable to acids
- stable to alkalis
- heat stable
- 80-90% loss during milling
268
List some food sources of niacin
| 4
- fortified breakfast cereals
- meat and offal
- bread
- nuts
269
List another source of niacin other than food
| 1
-produced in the intestine from the amino acid tryptophan
270
List the functions of niacin
| 3
- aids the metabolism of carbohydrates to release energy
- helps maintain healthy skin
- supports healthy nerve activity
271
List the effects of a deficiency of niacin
| 3
- tiredness and irritability due to a lack of energy
- pellagra
- delayed nerve impulses
272
Describe pellagra caused by a deficiency of niacin
| 2
- severe deficiency disease
| - symptoms include: Dermatitis, Diarrhoea, Depression, Dementia and it can eventually lead to Death
273
Describe what delayed nerve impulses due to a deficiency of niacin causes
(1)
-leads to cognitive impairment e.g. memory loss or disorientation
274
What is another name for vitamin B6
| 1
-pyridoxine
275
What are the properties of pyridoxine
| 5
- water soluble
- insoluble in fat
- heat stable up to 100 degrees, but some loss in cooking
- destroyed by oxygen
- destroyed by alkalis
- destroyed by light
276
List some sources of pyridoxine
| 6
- meat
- fish
- green vegetables
- nuts
- bananas
- offal
277
List the functions of pyridoxine
| 7
- aids the metabolism of carbohydrates to release energy
- aids the metabolism of protein to release energy
- aids the metabolism of fats to release energy
- relieves symptoms of pre-menstrual tension
- prevents nausea in early pregnancy
- supports healthy nerve activity
- prevents pyridoxine-dependent epilepsy in babies
278
List the effects of deficiency of pyridoxine
| 5
- tiredness and irritability due to a lack of energy
- PMT symptoms including mood swings, irritability, depression, anxiety and bloating
- nausea during pregnancy
- delayed nerve impulses
- convulsions and seizures in young babies
279
Describe what delayed nerve impulses due to a deficiency of pyridoxine causes
(1)
-leads to cognitive impairment, e.g. memory loss or disorientation
280
What is another name for vitamin k1?
| 1
-phylloquinone
281
What is another name for vitamin k2?
| 1
-menaquinone
282
What is another name for vitamin k3?
| 1
-menadione
283
Classify minerals into the two main groups
| 2
- macro nutrients
| - trace nutrients
284
What are macro minerals?
| 1
-required in relatively large amounts e.g. calcium, phosphorus, potassium and sodium
285
What are trace minerals?
| 1
-required in trace amounts, e.g. iron, zinc, iodine and flourine
286
What are some food sources of calcium?
| 4
- milk
- yoghurt
- tinned fish such as sardines
- nuts such as almonds
287
What is the RDA of calcium for children?
| 1
-800 mg
288
What is the RDA of calcium for adolescents?
| 1
-1,200 mg
289
What is the RDA of calcium for adults?
| 1
-800 mg
290
What is the RDA of calcium for pregnant or lactating women?
| 1
-1,200 mg
291
What are the functions of calcium?
| 4
- aids the formation of strong bones
- aids the formation of teeth
- assists blood clotting which is necessary if an injury causes damage to blood vessels
- aids normal muscle contraction
292
What are the effects of deficiency of calcium?
| 4
- increased risk of bone diseases, such as rickets, osteomalacia and osteoporosis
- increased risk of tooth decay
- slow blood clotting of ruptured blood vessels which can cause haemorrhaging
- muscles fail to relax after contraction. This can cause muscular spasms, cramps and convulsions
293
What are convulsions?
| 1
-convulsions are a condition where the muscles contract and relax repeatedly, causing an uncomfortable shaking of the body
294
How is calcium absorbed?
| 2
- it is absorbed bonded to a specific protein
| - only 20-30% of calcium is absorbed by the body
295
List the factors assisting the absorption of calcium
| 6
- lactose
- vitamin D
- the hormone parathormone
- oestrogen
- phosphorus
- an acid environment
296
Explain how lactose aids the absorption of calcium
| 1
-it makes calcium more soluble and easier to absorb
297
Explain how vitamin D aids the absorption of calcium
| 1
-it stimulates the production of calcium-binding protein, assisting absorption
298
Explain how the hormone parathormone aids the absorption of calcium
(1)
-it is released from the parathyroid gland, controls the levels of calcium in the blood
299
Explain how the hormone oestrogen aids the absorption of calcium
(1)
-produced in the ovaries, promotes calcium absorption
300
Explain how the phosphorus aids the absorption of calcium
| 1
-combines with calcium, creating calcium phosphate, which is easier to absorb
301
Explain how an acid environment is achieved to aid the absorption of calcium
(1)
-by consuming foods high in vitamin C
302
List the factors hindering the absorption of calcium
| 7
- tannins
- excess dietary fibre
- excess saturated fat
- excess protein
- phytic acid
- oxalic acid
- soft drinks
303
Explain how tannins hinders the absorption of calcium
| 2
- present in tea and coffee
| - binds to calcium, inhibiting absorption
304
Explain how dietary fibre hinders the absorption of calcium
| 1
-excess dietary fibre binds to calcium, inhibiting absorption
305
Explain how excess saturated fait hinders the absorption of calcium
(1)
-excess saturated fat binds with calcium, creating insoluble and non-absorbable calcium soaps
306
Explain how excess protein hinders the absorption of calcium
| 2
- as the body burns excess protein for energy it produces sulfate
- sulfate increases the amount of calcium excreted in urine
307
Explain how phytic acid hinders the absorption of calcium
| 1
-phytic acid in wholegrain bread and seeds binds to calcium, inhibiting absorption
308
Explain how oxalic acid hinders the absorption of calcium
| 1
-oxalic acid in rhubarb and spinach binds to calcium, inhibiting absorption
309
Explain how soft drinks hinder the absorption of calcium
| 1
-over consumption of soft drinks hinders absorption of calcium
310
What are the two forms of iron?
| 2
- haem iron
| - non-haem iron
311
What is haem iron also known as?
| 1
-ferrous iron
312
What is non-haem iron also known as?
| 1
-ferric iron
313
How is haem iron absorbed?
| 1
-it is absorbed easily by the body
314
How is non-haem iron absorbed?
| 2
- it is not easily absorbed by the body
| - it must be changed into ferrous iron to be easily absorbed
315
List some sources of haem iron
| 4
- red meat such as beef or lamb
- offal such as kidney or liver
- poultry such as chicken or turkey
- meat products such as black pudding
316
List some sources of non-haem iron
| 4
- cereals
- pulses such as lentils
- eggs
- leafy green vegetables such as spinach or cabbage
317
What is the RDA of iron for children and adult males?
| 1
-10 mg
318
What is the RDA of iron for adolescents and adult females?
| 1
-14 mg
319
What is the RDA of iron for pregnant or lactating women?
| 1
-15 mg
320
List the functions of iron
| 4
- makes red blood cells/forms haemoglobin
- forms part of myoglobin
- forms enzyme systems
- essential for the immune system
321
Explain the function of iron making red blood cells and forming haemoglobin
(1)
-makes red blood cells and forms haemoglobin, a red protein pigment found in red blood cells responsible for carrying oxygen around the body
322
Explain the function of iron forming part of myoglobin
| 1
-forms part of myoglobin, which carries oxygen to the muscles for energy
323
Explain the function of iron forming enzyme systems
| 1
-forms enzyme systems that aids the metabolism of food
324
List the effects of a deficiency of iron
- anaemia
- muscle fatigue
- less energy
- heart damage
325
Explain the effects of anaemia due to a deficiency of iron
| 3
- anaemia may occur due to a lack of haemoglobin and red blood cells
- causes a reduction in the oxygen levels in the blood
- symptoms include tiredness, pale skin, shortness of breath, irritability and dizziness
326
Explain the effects of muscle fatigue due to a deficiency of iron
(2)
- muscle fatigue due to a lack of oxygen as myoglobin is not being formed
- this decreases athletic performance
327
Explain the effects of less energy due to a deficiency of iron
(1)
-the body has less energy as food is not being broken down
328
Explain the affects of heart damage due to a deficiency of iron
(1)
-in severe cases anaemia can damage the heart
329
Explain how iron is absorbed by the body
| 1
-only 15% of iron intake is absorbed by the body
330
List the factors assisting iron absorption
| 4
- consuming haem iron only
- consuming haem with non-haem
- vitamin C
- acidity
331
Explain how consuming haem iron over non-haem aids absorption of iron
(!)
-it is easier to absorb
332
Explain how consuming haem iron with non-haem aids the absorption of iron
(1)
-consuming haem iron and non-haem iron together increases non-haem iron absorption
333
Explain how consuming vitamin C aids the absorption of iron
| 1
-consuming food high un vitamin C chemically changes non-haem iron to the more easily absorbed haem iron
334
Explain how acidity aids the absorption of iron
| 1
-acidity from hydrochloric acid (HCL) in the stomach chemically changes non-haem iron to the more easily absorbed haem iron
335
List the factors hindering the absorption of iron
| 5
- tannins
- excess dietary fibre
- phytic acid
- oxalic acid
- non-haem iron
336
Explain how tannins hinders the absorption of iron
| 1
-tannins present in tea and coffee bind to iron, inhibiting absorption
337
Explain how dietary fibre hinders the absorption of iron
| 1
-more than 35g of fibre a day causes it to bind to iron, inhibiting absorption
338
Explain how phytic acid hinders the absorption of iron
| 1
-phytic acid in wholegrain bread and seeds binds to iron, inhibiting absorption
339
Explain how oxalic acid hinders the absorption of iron
| 1
-oxalic acid in rhubarb and spinach binds to iron, inhibiting absorption
340
Explain how choosing non-haem iron sources hinders the absorption of iron
(1)
-choosing non-haem iron sources only because little of it is absorbed
341
List sources of zinc
| 6
- meat
- pulses
- milk
- seafood e.g. oysters
- eggs
- seeds e.g. sesame
342
What is the RDA of zinc for children?
| 1
-4-7mg
343
What is the RDA of zinc for adolescents and adults?
| 1
-7-10mg
344
What are the functions of zinc?
| 6
- aids the metabolism of fats to release energy
- aids the metabolism of carbohydrates to release energy
- aids the metabolism of protein to release energy
- helps the healing of wounds and repair of tissues
- helps maintain healthy skin and hair
- fights infection
345
What are the effects of a deficiency of zinc?
| 3
- tiredness and irritability due to a lack of energy
- impaired wound-healing, which can lead to infection
- hair loss and dry skin conditions, e.g. eczema
346
What are some sources of iodine?
| 5
- seafood
- meat
- cod liver oil
- seaweed e.g. nori
- milk
347
What is the RDA of iodine for children?
| 1
-70-100 microgram
348
What is the RDA of iodine for adolescents and adults?
| 1
-120-130 micrograms
349
What are the functions of iodine?
| 3
- aids the manufacture of the hormone thyroxine in the thyroid gland, which regulates metabolism
- essential for normal growth and development during gestation and childhood
- maintains the thyroid gland, preventing swelling and breathing difficulties
350
What are the effects of deficiency of iodine?
| 4
- reduced basal metabolic rate, increasing the risk of obesity due to lack of thyroxine
- stunted or delayed physical or mental growth in children called cretinism
- goitre, an abnormal enlargement of the thyroid gland in the neck and causes breathing difficulties
- increased risk of miscarriage and still birth
351
What are some sources of sodium (salt)?
| 5
- table salt
- cheese
- snack foods e.g. crisps
- white bread
- cured meats e.g. bacon
352
What is the RDA of sodium for children?
| 1
-1.6g (4g of salt)
353
What is the RDA of sodium for adolescents and adults?
| 1
-2.4g (6g salt)
354
What are the functions of sodium?
| 4
- regulates blood pressure
- supports healthy nerve activity
- aids normal muscle contraction
- controls water balance in the body
355
What are the effects of deficiency of sodium?
| 3
- low blood pressure (hypotension), reducing oxygen getting to organs as blood flow is slowed down
- delayed nerve impulses leading to cognitive impairment, e.g. memory loss or disorientation
- muscle fail to relax after contraction. This can cause muscular spasms, muscle cramps and convulsions
356
What does overconsumption of sodium cause?
| 3
- increase blood pressure
- increase the risk of heart attacks
- increase the risk of strokes
357
How do you reduce your consumption of sodium?
| 4
- avoiding high-salt snack foods e.g. unsalted nuts
- buying reduced salt products
- not adding salt when cooking e.g. herbs instead
- reading nutritional labels carefully when shopping as food may contain hidden sodium, e.g. monosodium glutamate, a sodium salt
358
What are some sources of potassium?
| 5
- meat
- bananas
- leafy green vegetables
- milk
- fish
359
What is the RDA of potassium of children?
| 1
-0.8-2g
360
What is the RDA of potassium of adolescents and adults?
| 1
-3.1g
361
What are the functions of potassium?
| 5
- aids the metabolism of carbohydrates to release energy
- aids the metabolism of protein to release energy
- supports healthy nerve activity
- aids normal muscle contraction
- healthy cell formation
362
What are the effects of deficiency of potassium?
| 4
- tiredness and irritability due to lack of energy
- delayed nerve impulses leading to cognitive impairment, e.g. memory loss or disorientation
- muscle fail to relax after contraction. This can cause muscular spasms, muscle cramps and convulsions
- cardiac arrest
363
What is water the main component of?
| 4
- cell liquid
- blood
- lymph
- digestive juices
364
What is the elemental composition of water?
| 1
-water is made up of the elements hydrogen and oxygen in a 2:1 ratio
365
What are the properties of water?
| 9
- colourless
- odourless
- tasteless
- boils at 100 degree Celsius
- freezes at 0 degree Celsius
- neutral pH 7
- excellent solvent
- can be solid, liquid or gas
- absorbs and retains heat
366
What are the functions of water?
| 6
- quenches thirst
- removes waste products from the body through the kidneys as urine
- makes up 92% of blood plasma, which helps to transport nutrients, oxygen, carbon dioxide, hormones and enzymes around the body
- provides the minerals calcium and fluoride
- regulates body temperature at 37 degrees Celsius
- is involved in the hydrolysis of nutrients during digestion
- prevents constipation, as it makes stools soft and easy to pass
367
What are some sources of water?
| 4
- tap or bottled water
- beverages, e.g. milk, tea, coffee and juices
- fruit and vegetables
- soups
368
What is the recommended daily intake of water?
| 2
- consume two to three litres per day
- fluid requirements increase in certain circumstances including intense physical activity, lactation, diarrhoea and illness, e.g. a fever
