Nutrition Flashcards
1
Q
what are the required nutrients
A
calcium
phosphorus
vitamin A, C and D
fluoride
protein
2
Q
what is nutrition
A
processes whereby cellular organelles, cells, tissues, organs and the body as a whole obtain and use necessary substances from foods to maintain structural and functional integrity
3
Q
how many calories should women consume per day
A
2000
4
Q
how many calories should men consume per day
A
2500
5
Q
what is the SACN
A
scientific advisory committee on nutrition
6
Q
which nutrients prevent deficiency symptoms
A
folic acid and megaloblastosis
7
Q
which nutrients optimise stores in the body
A
folic acid and plasma/tissue levels
8
Q
which nutrients optimise biochemical or physiological function
A
folic acid to minimise plasma homocysteine
9
Q
which nutrients optimise a risk factor for a disease
A
sodium to minimise hypertension
10
Q
which nutrients minimise incidence of a disease
A
folic acid to minimise NTD in newborns
11
Q
what are the three main classes of nutrients
A
macronutrients
micronutrients
water
alcohol
12
Q
what are the macronutrients
A
carbohydrates
proteins
fats and oils
13
Q
what are the micronutrients
A
minerals and vitamins
14
Q
what is the primary concern when looking at nutrition
A
the use of chemical energy like carbohydrates, fats and proteins for the different energy requirements in the body
15
Q
what are the four energy forms in the body
A
electrical
chemical
mechanical
heat
16
Q
what is an example of electrical energy in the body
A
maintainenance of ionic gradients
17
Q
what is an example of chemical energy in the body
A
protein synthesis
18
Q
what is an example of mechanical energy in the human body
A
muscle contraction
19
Q
what is an example of heat energy in the human body
A
maintenance of body temperature
20
Q
what are the two main ways of measuring energy
A
calorie
joule
21
Q
what is a calorie
A
the energy needed to raise the temperature of one gram of water from 14.5 to 15.5 celcius
22
Q
what is a joule
A
the energy used when one gram is moved one metre by the force of one newton
23
Q
how many joules is one megajoule
A
1,000,000
24
Q
how many joules is one calorie the equivalent of
A
4.184
25
how to convert kcal to kJ
1:4.184
26
how to convert MJ to kcal
1 MJ to 239 kcal
27
what does energy come from
macronutrients and alcohol
28
how many kcal in fat
37kj per gram of fat
29
how many kcal in alcohol
29kj per gram
30
how many kcal in protein
17 kj per gram
31
how many kcal in carbohydrate
16 kj per gram
32
what is the energy density
the energy a food contains per gram
33
which nutrient is the most energy dense
fat
34
how to measure the total energy content of food
burn it and measure the heat released
35
which foods have low energy density
those with few calories per gram
36
what is TEE
total energy expenditure
37
what are the components of TEE
basal metabolic rate
physical activity
thermogenesis
additional requirement for growth
38
what is the basal metabolic rate
vital body functions like maintaining the electrochemical gradient, cell and protein turnover, lung and heart functions use the BMR
39
what composition of TEE is basal metabolic rate
60 to 75%
40
what is physical activity energy used for
muscular work
41
what composition of TEE is physical activity
10-40%, can go up to 70%
42
what uses thermogenesis energy
metabolising food
muscle action
climate
43
what composition of TEE is thermoegenesis
10-20%
44
what are the storage forms of energy
fat
glycogen
protein
45
what is the major store for energy
fat
46
which energy store is rarely used
rarely, only when starving
47
when is energy balance achieved
when energy intake = energy output
48
how many kcal consumed per year
1,000,000
49
when is a positive energy balance required
during growth, pregnancy and lactation
50
what happens when there is negative energy balance
over the medium term, the fat stores are used for energy.
over the long term, protein will also be used for energy
can lead to health problems
51
which factors can affect energy requirements
body size
age
activity
pregnancy/lactation
disease, trauma, and treatments
52
why does body size affect energy requirements
more energy needed for bigger people, especially in terms of muscle mass
53
why does age affect energy requirements
more energy in early years, like in growth and activity, and less in later years
54
why does activity affect energy requirements
more energy for more activity
55
why does disease and trauma affect energy requirements
fever and stress can increase metabolic rate, and medications can increase or decrease the rate
56
how can energy expenditure be measured
direct calorimetry
indirect calorimetry
doubly labelled water
57
what does measurement of energy intake assume
the population is in energy balance and the intake data is accurate
58
what is used to estimate basal metabolic rate
the henry equation
59
what are carbohydrates
compounds made of carbon, hydrogen and oxygen
they provide energy, a total of 40-80% of total energy intake
60
why are carbohydrates difficult to classify
nutritional, chemical or other
61
what are the different chemical classifications of carbohydrates
monosaccharide
disaccharide
polysaccharide
62
what are the nutritional classifications of carbohydrates
sugars
starches
non starch polysaccharides
63
name some oligosaccharides
raffinose
stachyose
verbascose
fructans
64
describe disaccharides
form of free sugar, such as sucrose, lactose, maltose and trehalose
65
describe sugar alcohols
sorbitol
mannitol
dulcitol
inositol
free sugar examples
66
describe monosaccharides
glucose
fructose
mannose
ribose
deoxyribose
example of free sugar
67
describe starch
a polysaccharide
amylose and amylopectin
68
what is cellulose
non starch polysaccharide
69
what are the three principle food carbohydrates
polysaccharides
dextrins
free sugars
70
what are polyols
sugar alcohols
71
what are intrinsic sugars
fructose
glucose
those found in food and vegatables
72
describe extrinsic sugars
milk and milk products
non milk products
73
describe non milk extrinsic sugars
mostly sucrose, used as table sugar and baked goods
also found in honey and fruit juices
74
describe milk products extrinsic sugars
lactose
75
what are free sugars
monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and unsweetened fruit juices
76
what are added sugars
these are sugars and syrups that are added during manufacture and preparation but do not capture the sugars present in unsweetened fruit juice or honey
77
what are total sugars
describes the total amount of sugars from all sources
78
what are sugar alcohols
these are found natrually, or commercially from glucose.
they are used in diabetic products, and are absorbed from the gut more slowly so they have less of an effect on blood glucose
79
what are oligosaccharides
these are short chain carbohydrates, and are found in plant seeds, peas and beans.
they cannot be broken down by the digestive enzymes and are instead fermented in the large intestine
80
what are dextrins
these are short chains of glucose, formed by the degradation of starch by partial hydrolysis, and are used in oral tube feeding preparations
81
what is glycogen
this is a storage carbohydrate in humans and animals
82
what is starch
a storage carbohydrate in cereal grains and potatoes.
they also exist in granules
83
what are the two main types of starch
amylose and amylopectin
84
what is amylose
unbranched chain of glucose with alpha 1-4 linkages
85
what is amylopectin
long, branched polymer.
15-30 glucose units 1-4, and the branches are linked by 1-6 linkages
86
describe the characteristics of amylopectin
insoluble in water, and are indigestable when raw
the process of cooking makes it digestible
broken down by amylase
87
what is dietary fibre
the portion of food derived from cellular walls of plants which is digested very poorly by human beings
88
what are the three categories of dietary fibres
non starch polysaccharides
resistant oligosaccharides
resistant starch
89
what is the best index of dietary fibres
non starch polysaccharides
90
describe non starch polysaccharides
these provide structure in plant cell walls, and are fermented in the large intestine by bacteria
they produce volatile fatty acids that are used for energy
91
what are the soluble NSPs
oats beans pulses fruits and vegetables
they have a cholesterol loweing effect
92
describe insoluble NSP
found mainly in wheat bran, has a faecal bulking effect as it absorbs water, adds bulk and decreases the transit time
93
what is meant by resistant starch
this is starch and starch degradation products that are not fully digested in the small intestine of humans
94
describe RS1
found enclosed within cell walls structures like wheat or oats flakes
95
describe RS2
presence of raw starch granules, like green bananas and uncooked potatoes
96
describe RS3
retrograded starch like potato salad
97
describe RS4
chemically modified starch, modified starch is added to processed food
98
which oligosaccharides are included in the dietary fibre category
inulin
fructo oligosaccharides
99
which carbohydrate bonds can be digest
alpha 1-4
alpha 1-6
glucose fructose
glucose galactose
100
what digests the 1-4 linkage
amylase
101
what digests the 1-6 linkage
glucoamylase
102
what digests the glucose fructose
sucrase
103
what digests the glucose galactase
lactase
104
what happens to food not digested in the small intestine
it is fermented by the colonic microflora to short chain fatty acids and gases
this includes acetic, propionic, and butyric acid
105
describe acetic acid
60% of total SCFA
acts as an energy source
the only form of SCFA to reach peripheral blood to increase lipid production
106
describe the actions of propionic acid
removed by the liver, may reduce cholesterole synthesis, can be used to make glucpse
stimulates gut cell proliferation
107
describe the action of butyric acid
main fuel of colonocytes, removed by mucosa, stimulates apoptosis, differentiation of cancer cells in vitro, several stages of cancer in vitro and gut cell proliferation
108
how many grams of fibre per day for 16+ people
30
109
what composition of average daily carbohydrate intake is from cereal and cereal products
46%
110
what are fats made up of
carbon
hydrogen
oxygen
111
what are the roles of dietary fats
energy
essential fatty acids
fat soluble vitamins
112
what are the roles of lipids in the body
store of energy
structural role in cell membranes
metabolic functions
113
which type of fat is most commmonly found in foods
triaclyglycerols
114
characteristics of fats
oily
insoluble in water
derivatives of fatty acids
115
what is the structure of triacylglycerols
glycerol and 3 fatty acids
116
what is the structure of phospholipids
phosphorus and 2 fatty acids
117
what is the structure of free cholesterol or cholesterol ester
1 fatty acid
118
what are the structural factors affecting properties of fatty acids
number of carbon atoms
presence of double bonds
119
what are cis fats
configuration of double bonds in naturally occurring unsaturated fats like vegetable oils
120
what are trans fats
these have at least one double bond in trans configuration
121
what are the roles of essential fatty acids
cell membranes
biologically active compounds like eicosanoids
growth and development
122
what do prostacyclins do
inhibit platelet aggregation and relax arterial walls
123
what do thromboxanes do
they stimulate platelet aggregation and contract the arterial walls
124
leukotriene action
promote inflammation
125
how much of food energy is taken up by monosaturates
13%
126
describe proteins functions
proteins are major structural and functional components of all cells
they have structural and functional roles that are needed for growth and maintenance
provides about 10-15% of dietary energy supply
127
describe conditionally essential amino acids
these are synthesised in certain situations like in growth and childhood
128
describe fibrous proteins
elastic, single alpha helix like keraton in wool
or
inelastic, more than one alpha helix like collagen in bone
129
describe globular proteins
single folded chain like myoglobin
or
more than one folded chain like in haemoglobin
130
how many different proteins in the body
30,000 to 50,000
131
what are the possible biological values of proteins
high biological
low biological
limiting amino acid
