Chapter 5 Flashcards
The structure of nutrients (143 cards)
1
Q
what chemical elements make up protein?
A
carbon, hydrogen, oxygen, nitrogen, phosphorus and sulphur
2
Q
what is a polymer?
A
a general name for a substance that is mainly made up of a large number of similar units bonded together
3
Q
how are proteins arranged?
A
amino acids which join together to form long chains (polymers) to form protein molecules
4
Q
what is the carboxyl group?
A
COOH
5
Q
what is the side chain?
A
R
6
Q
what is the amino group?
A
NH2
7
Q
how are amino acids joined to other amino acids?
A
peptide bonds when the amino group of 1 amino acid reacts with the carboxyl group of another amino acid with the loss of one molecule of water = condensation reaction
8
Q
what is a polypeptide?
A
when many amino acids are joined together in long chains
9
Q
what are the four stages of folding protein molecules?
A
- PRIMARY - polypeptide chain
- SECONDARY - a helix shape or a b pleated sheet
- TERTIARY - polypeptide chain folds more and the protein molecule becomes compact and more bonds are formed
- QUATERNARY - several folded polypeptide chains join and fold together to form compact bundles
10
Q
what is hydrophilic/hydrophobic?
A
a substance that is attracted to water/a substance that repels water and will not mix with it
this affects how the chains fold or twist
11
Q
what is denaturation of proteins?
A
the breaking of bonds that hold protein molecules together and cause them to unravel. e.g. heat, mechanical action and pH
12
Q
digestion of proteins
A
breaking something down into its component parts. The long chains of proteins are broken down into amino acids by substances called enzymes in the stomach and small intestine
13
Q
how to enzymes work for proteins?
A
speed up chemical reactions by breaking the peptide bonds between amino acids by putting back a molecule of water = hydrolysis reaction
the free amino acids are then absorbed into the bloodstream and are taken to liver
13
Q
essential amino acids
A
cannot be made by body and must be supplied ready made by food e.g. leucine, lysine and valine
14
Q
non essential amino acids
A
can be made in the body by reorganising those that are absorbed during digestion e.g. glycine, proline and serine
15
Q
HBV/LBV
A
if they contain all of the essential amino acids they are HBV but if they are missing one or more essential amino acid they are LBV
16
Q
conditionally essential amino acids
A
amino acids that must be obtained ready made from food for a particular stage of life e.g. arginine and histidine
17
Q
sources of protein
A
LBV - fruit, veg, nuts and seeds
HBV - meat, fish, dairy and eggs
18
Q
what chemicals are lipids made up of?
A
carbon, hydrogen and oxygen
19
Q
what chemical elements are lipid molecules arranged into?
A
triglycerides = 3 fatty acids and 1 glycerol
19
Q
what type of reaction takes place for lipids?
A
condensation reaction
19
Q
saturated fatty acids/unsaturated fatty acids
A
saturated contain as many hydrogen atoms as they can take and are full in capacity
unsaturated are not full to capacity as they contain one or more double bonds
19
Q
what is hydrogenation
A
solid fats are made from liquid oils by the food industry e..g. vegetable fat spreads where hydrogen atoms are added to unsaturated fatty acids to make them saturated
20
Q
monounsaturated/polyunsaturated
A
mono = fatty acid that has 1 double bond
poly = fattty acids that have 2 or more double bonds
21
saturated fatty acids
straight, packed tightly together to form a rigid solid, solid at room temperature e.g. butter
22
unsaturated fatty acids
molecules contain double bonds either in cis or a trans formation
23
cis
the two hydrogen atoms are on either side of the double bond and are on the same side of the carbon chain and the molecule bends due to the rigidity of the double bond
the more cis double bonds a fatty acid contains the more curved it becomes
24
trans
the two hydrogen atoms are on opposite sides of the carbon chain which means the molecule doesn't bend and remains straight
there is evidence that trans fats are linked to increased risk of heart disease and other diet-related diseases
25
sources of fats
visible - plant = oil, avocado, nuts
- animals = meat, fish, milk
invisible = cakes, ice cream, crisps, doughnuts
26
digestion of fats
fats are digested by enzymes are once absorbed are carried around the bloodstream attached to proteins as lipoproteins
27
rancidity of fats
an oil or fat becomes rancid when oxygen is allowed to break it down by oxidation which causes unpleasant odours and flavours and destroys some nutrients in food
oils higher in unsaturated fatty acids are more prone to rancidity than oils high in saturated fat because of the number of double bonds they contain making them harder to break up
28
why are antioxidants added to various products?
to prevent or slow down the rancidity of the fats that they contain e.g. meat and poultry
29
what chemical elements are carbohydrates made up of?
carbon, hydrogen and oxygen
30
what is the chemical formula for carbohydrates?
C6H12O6
31
how are carbohydrates formed due to photosynthesis?
6C02+6H20 ________> C6H12O6 + 602
32
what are the 2 groups of carbohydrates divided into?
simple carbohydrates (sugars)
complex carbohydrates (polysaccharides)
33
what are the 2 groups of simple carbohydrates called?
monosaccharides and disaccharides
34
monosaccharides
one sugar molecule (glucose, fructose and galactose)
glucose - ripe fruits and veg = hexose ring
fructose - fruit sugar, honey, plant juice = pentose ring
galactose - breast milk = hexose ring
35
disaccharides
two monosaccharides joined together by a condensation reaction due to a glycosidic bond with the loss of a molecule of water(sucrose, lactose and maltose)
sucrose - glucose+ fructose
lactose - glucose+galactose
maltose - glucose+glucose
36
polysaccharides
insoluble in cold water, made from glucose molecules joined together in different formations
37
starch
made of glucose molecules joined together in straight chains and branches and stored inside microscopic granules in plants
38
dextrin
formed when starchy foods are baked or toasted, forms part of the crust
39
cellulose
formed from many glucose molecules joined in such as way that humans cannot digest them but of great importance to the body as dietary fibre which is needed to get rid of solid waste products.
the molecules are arranged in long, straight lines so cellulose is firm and strong
also known as non starch polysaccharide
40
pectin
formed from lots of glucose molecules joined together in a complex web forms a gel with water to make the structure of jams when boiled with sugar and acid and then cooled
41
glycogen
the only polysaccharide made by some animals, including humans. Formed from many glucose polymers as a store of energy in the liver and muscles
42
what 2 components does starch consist of?
amylose = 20%
amylopectin = 80%
both of these are polymers of glucose molecules
43
dietary fibre
important for assisting the movement of solid waste e.g. cellulose, pectins etc products along the GI tract and their removal from the body and are referred to as insoluble/soluble fibre
44
soluble fibre
in the intestines soluble fibre dissolves in water to form a gel thickens and softens faeces and makes them easier to eliminate from the body
45
insoluble fibre
does not absorb or dissolve in water but passes through the digestive system largely unchanged. It provides the bulk to the faeces to help waste products be easily eliminated from the body
46
glycogenesis
the formation of glycogen in the body which occurs in the liver. It is controlled by enzymes, hormones and calcium ions
47
glycogenolysis
the process that breaks down glycogen in the liver and muscles in order to release glucose for energy
48
sources of carbohydrates
monosaccharides - glucose, fructose and galactose
disaccharides - sucrose, maltose and lactose
polysaccharides - starch, dextrin, pectin, cellulose and glycogen
49
digestion of carbohydrates
begins in the mouth and ends in the small intestine they are broken down by hydrolysis except dietary fibre such as cellulose
50
vitamin A
retinol
51
sources of vitamin a
animal = milk, cheese, butter and eggs
plant (beta carotene) = spinach, red/orange/yellow fruits and veg
52
functions of vitamin a
-healthy skin
-growth of children (retinol converted to retinoid acid)
-moist and healthy mucus membranes
-antioxidant
-help to see in dim light
53
deficiency of vitamin a
-dry and infected skin and mucous membranes
-night blindness
-poor growth in children
54
excess of vitamin a
-poisonous if too much is taken e.g. in supplements especially to unborn babies
55
vitamin d
cholcalciferol
56
sources of vitamin d
-sunlight on skin (biogenesis of vitamin d)
-food = oily fish, meat, eggs, butter, vegetable fat spreads and fortified breakfast cereals
57
functions of vitamin d
-involved in the production of red blood cells
-functioning of the immune system
-absorption of calcium
58
deficiency in vitamin d
bones weaken and bend = rickets in children and osteomalacia in adults
59
vitamin e
alpha -tocopherol
60
sources of vitamin e
soya, olive oil, nuts, seeds and whole wheat
61
functions of vitamin e
antioxidant (helps to prevent heart disease and cancers)
62
vitamin k
phylloquinone
63
sources of vitamin k
green leafy vegetables, green tea, cheese and liver
64
functions of vitamin k
helps blood to clot after an injury
65
b1
thiamine
66
sources of b1
meat, cheese, eggs, wholemeal flour, vegetables and fresh/dried fruits
67
functions of b1
-energy release from carbohydrates
-nerve function
-production of DNA and RNA
68
deficiency of b1
beri beri - affects nerves and muscles
69
b2
riboflavin
70
sources of b2
milk, eggs, mushrooms, fortified breakfast cereals and rice
71
functions of b2
-energy release from carbohydrates, fats and proteins
-converting retinol to retinoid acid
-production of b6
72
deficiency of b2
rare - sore corners of mouth
73
b3
niacin
74
sources of b3
beef, pork, eggs and milk
75
functions of b3
-involved in many metabolic reactions e.g. respiration
-range of enzyme reactions
76
deficiency of b3
pellagra 3DS = diarrhoea, dementia and dermatits
77
vitamin b5
pantothenic acid
78
sources of b5
nuts, green leafy vegetables, milk, eggs and beans
79
functions of b5
converted to coenzyme A which is involved in the metabolism of proteins, fats and carbohydrates during respiration
80
deficiency in b5
-fatigue
-insomnia
-depression
-stomach upsets
-burning feet
81
b6
pyridoxine
82
sources of b6
red meat, milk, avocados, oily fish
83
functions of b6
coenzyme involved in:
-metabolism of fatty acids, protein and glycogen
-synthesis of coenzyme A
-incorporating iron into haemoglobin
84
deficiency of b6
-cracks at corners of mouth, dry, scaly lips
-swollen tongue
-depression
-weakened immune function
85
b7
biotin
86
sources of b7
milk, oily fish, eggs, cheese, nuts
87
functions of b7
-coenzyme involved in the production of fatty acids
-needed for gluconeogenesis
88
deficiency in b7
-hair loss, scaly red rash on face
-depression, legsrthy, numbness and tingling sensation in hands and feet
89
b9
folate
90
sources of b9
green leafy vegetables, wholegrain rice, fruits, chickpeas
91
functions of b9
-makes healthy red blood cells
-production and repairing of DNA
-cofactor in metabolic reactions especially in growth of embryo and foetus in pregnancy
-helps to prevent spinal cord defects in unborn babies
92
deficiency in b9
-megaloblastic anaemia
-spina bifida in newborn babies
93
b12
cobalamin
94
sources of b12
liver, meat, fish, cheese, fortified breakfast cereals
95
functions of b12
-coenzyme in the metabolism of proteins, lipids and carbohydrates
-production and control of DNA
-makes healthy red blood cells
-makes healthy nerve cells
96
deficiency in b12
pernicious anaemia
97
vitamin c
ascorbic acid
98
sources of vitamin c
fruits and vegetables (especially citrus fruits), cabbage, milk and liver
99
functions of vitamin c
-absorption of iron
-cofactor in enzymic reactions in the production of collagen in connective tissue which binds body cells together
-antioxidant
100
deficiency in vitamin c
-anaemia
-bleeding under skin
-loose teeth
-wounds do not heal
-scurvy
101
sources of calcium
canned fish, milk, cheese, green leafy vegetables
102
functions of calcium
-main component of hydroxyapatite which makes strong bones and teeth
-calcium ions in the blood are required to:
make nerves and muscles work correctly
help blood clot after an injury
103
deficiency in calcium
-bones and teeth weaken
-bones bend
-nerves and muscles don't work properly = tetany
-blood will not clot after injury
104
sources of magnesium
chlorophyll in dark green leafy vegetables, avocados, seeds, beans, whole grains
105
functions of magnesium
-essential for cell metabolism
-involved in vitamin d metabolism
-used by many enzymes to make them work
-metabolism of ATP, DNA and RNA
106
deficiency of magnesium
-increased risk of abnormal heartbeat=cardiac arrest
-loss of appetite
-personality changes
-tremor, poor coordination and muscle spasms
107
sources of phosphorus
present in all animal and plant cells
108
functions of phosphorus
-strong bones and teeth (hydroxyapatite)
-found in ATP, DNA and RNA
-energy release
-important element of cell membranes
109
excess of phosphorus
infants are fed too much unmodified cow's milk
110
sources of potassium
almost all unprocessed foods especially fruits and vegetables
111
functions of potassium
needed for function of all cells especially nerve cell function particularly in heart muscle
112
deficiency of potassium
-weakness and fatigue
-muscle cramps and aches
-tingling and numbness
-heart palpitations
-breathing problems
-digestive aches and upsets
113
sources of sodium
salt, salted foods, cheese, yeast extracts, gravies, takeaway foods
114
functions of sodium
-main electrolyte in extracellular fluid
-controls pressure and volume of fluids in body
-makes nerves and muscles work properly
115
deficiency of sodium
muscle cramps
116
excess of sodium
high blood pressure and cardiovascular disease
117
what are the 2 types of iron
haem and non haem iron
118
what are sources of haem iron
red meat, kidney, liver, egg yolk
119
what are the sources of non-harm iron
wholemeal bread, green leafy veg, dark chocolate and needs vitamin c to enable it to be absorbed
120
functions of iron
-makes haemoglobin in red blood cells to carry oxygen to all body cells to produce energy
-involved in function of many enzymes
121
deficiency of iron
-iron deficiency anaemia
-tiredness and lack of energy
-weakness
-pale skin complexion
-weak and split nails
122
excess of iron
-poisonous if too much taken
123
sources of iodine
seafood, vegetable, dairy foods
124
functions of iodine
makes thyroxin in thyroid gland to control metabolic rate of the body
125
deficiency of iodine
goitre (swelling of the neck)
126
sources of fluoride
seafood, fish, tea and some water supplies
127
functions of fluoride
strengthens tooth enamel and bones
128
deficiency of fluoride
weak enamel - more chance of tooth decay
129
excess of fluoride
discoloured teeth (florosis)
130
sources of zinc
readily absorbed from meat and present in many foods
131
functions of zinc
-present in many enzymes
-involved in metabolism of DNA and RNA
132
deficiency of zinc
-stunted growth of children
-immune function is affected
-sensation of taste is reduced
-dwarfism
-delayed sexual maturation
-hair may lose colour
133
water intake
the beverages, solid food and the product of a number of chemical reactions in the cells
134
water output
the amount of water that leaves the body in urine, faeces, respiration and through the skin
135
factors that affect water output
high temperature, humidity and exercise
136
what hormone controls water in the body
ADH hormone regulates how much water is conserved or released by the kidneys and regulates thirst
137
intracellular fluids
all the water and electrolytes within cells
138
extracellular fluids
includes all water and electrolytes outside of cells
139
dehydration
-headache, nausea, weakness and hyperthermia
-wrinkled skin that doesn't spring back when pinched
-skin folding on the forehead
-significantly decreased urine output
-very concentrated urine
-sunken eyes
-dry mucous membranes in the mouth and nose
-blood pressure changes
-tachycardia - abnormally rapid heart rate
