Diet + Nutrition

Question 1

3 reasons we need food

Answer 1

• ‘fuel’ for energy
• provide materials for growth and repair of tissues
• help fight against disease and keep bodies healthy

Question 2

5 groups of food substance you NEED as well as water and fibre and at the right amounts to be balanced

Answer 2

carbohydrates
lipids
proteins
minerals
vitamins

Question 3

what is the bodes main fuel

Answer 3

carbohydrates

Question 4

how do cells release energy from carbs

Answer 4

by oxidising a sugar called glucose (respiration)

Question 5

glucose is found in what

Answer 5

sweet tasting foods like fruits and veg

Question 6

different types of sugar other than glucose

Answer 6

fructose and lactose and sucrose (table sugar)

Question 7

2 physical properties of sugar

Answer 7

taste sweet

can dissolve in water

Question 8

many processed foods contain added sugar which causes common problems today like

Answer 8

tooth decay
obesity
diabetes

Question 9

most carbs found in our diet come from

Answer 9

starch

Question 10

what is starch

Answer 10

large insoluble molecule found in carbs, because insoluble found as a storage energy in things like potatoes and rice

Question 11

what is starch’s structure

Answer 11

a polymer of glucose, made up of long chains of hundreds of glucose molecules

Question 12

starch is found in only plant cells so what is found in animal cells which is very similar

Answer 12

glycogen (another polymer of glucose), store of energy in muscles etc

Question 13

there is an enzyme our body does NOT produce to breakdown … into simple sugars for our blood or as an energy source

Answer 13

cellulose (another polymer of glucose)

Question 14

if we cannot digest cellulose why do we need it

Answer 14

forms dietary fibre for us –> gives the muscles of the gut something to push against as the food is moved through the intestine (avoiding constipation and preventing bowel diseases)

Question 15

lipids contain the same elements in their molecules as carbohydrates which are

Answer 15

carbon
hydrogen
oxygen (less of this in lipids)

Question 16

animal fats are usually solid at room temperature and what are plant fats state at room temperature

Answer 16

usually liquid (oils)

Question 17

why are lipids important for humans

Answer 17

make up about 10% of our body mass and form an essential part of the structure of all our cells

Question 18

what is the fatty layer under our skin useful for

Answer 18

used for insulation, reducing heat loss at the surface of our body

Question 19

what are the chemical building blocks of lipids

Answer 19

glycerol (oily liquid) and fatty acids

Question 20

explain the structure of glycerol

Answer 20

joined to three fatty acid molecules

Question 21

too much lipids however can cause what

Answer 21

heart disease from too much saturated fat or high cholesterol

Question 22

how much of our body mass do protein make sup

Answer 22

18% –> second largest fraction after water

Question 23

why are proteins important for us

Answer 23

all cells contain them so needed for growth and repair of tissues, enzymes are made up of them

Question 24

what are products that are rich in proteins

Answer 24

animal products like meat, fish, cheese, eggs and then beans, peas and nuts

Question 25

doctors recommend a daily intake of protein of 70g, but in poorer countries they suffer from a lack of protein leading to

Answer 25

kwashiorkor

Question 26

what is proteins structure like

Answer 26

20 different sub-units called amino acids

Question 27

what do amino acids contain

Answer 27

carbs/fats and nitrogen

two also contain sulphur

Question 28

what are amino acids structure like

Answer 28

linked together in a long chain which are folded/twisted into spirals with cross-links holding the chains together, all in any order resulting in thousands of different structures and specialist cells

Question 29

explain calciums roll as a mineral in our body

Answer 29

making teeth and bones, 100g in an adults body, comes from dairy products, fish, bread and vegetables

Question 30

explain irons roll as a mineral in our body

Answer 30

part of haemoglobin in red blood cells, helps carry oxygen, 3g found in an adults body, found in red meat, liver, eggs and some vegetables

Question 31

what happens if a person fails to intake the required amount of minerals

Answer 31

start to show symptoms of mineral deficiency disease and could lead to rickets or anaemia

Question 32

Use in the body, effect of deficiency, some foods that have a lot of it: Vitamin A

Answer 32

making a chemical in the retina; also protects the surface if the eye
night blindness, damages cornea of eye
fish liver oils, liver, butter, carrots

Question 33

Use in the body, effect of deficiency, some foods that have a lot of it: Vitamin B1

Answer 33

helps with cell respiration
beri-beri
yeast extract, cereals

Question 34

Use in the body, effect of deficiency, some foods that have a lot of it: Vitamin B2

Answer 34

helps with cell respiration
poor growth, dry skin
green veg, eggs, fish

Question 35

Use in the body, effect of deficiency, some foods that have a lot of it: Vitamin B3

Answer 35

helps with cell respiration
pellagra
liver, meat, fish

Question 36

Use in the body, effect of deficiency, some foods that have a lot of it: Vitamin C

Answer 36

sticks together cells lining surfaces such as the mouth
scurvy
fresh fruit and vegetables

Question 37

Use in the body, effect of deficiency, some foods that have a lot of it: Vitamin D

Answer 37

helps bones absorb calcium and phosphate
rickets, poor teeth
fish liver oils, sunlight

Question 38

test for starch

Answer 38

• starch powder placed on spotting tile
• drop of dilute iodine solution added to starch
• reacts with starch forming very dark blue or blue/black
• can use any starchy substance
• will stay iodine colour if no starch is present

Question 39

test for glucose

Answer 39

• glucose is called a reducing sugar as the test for it involves reducing an alkaline solution of copper(II) sulcate to copper(I) oxide
• small spatula placed in test tube (add a little water)
• dissolve the glucose
• add several drops of Benedict’s solution to the test tube
• it will go blue
• place the tube in a boiling water bath
• the blue colour gradually changes colour to orange in a few seconds or brick red precipitate of copper(I) oxide
• this works with all types of sugars except sucrose (table sugar)

Question 40

who needs for calories per day: male or female

Answer 40

male

Question 41

who needs for calories per day: new born baby or 2 year old child

Answer 41

2 year old

Question 42

who needs for calories per day: girl aged 12-14 or girl aged 15-17

Answer 42

the same

Question 43

who needs for calories per day: boy aged 12-14 or boy aged 15-17

Answer 43

boy ages 15-17

Question 44

who needs for calories per day: girl aged 15-17 or boy aged 12-14

Answer 44

boy aged 12-14

Question 45

who needs for calories per day: heavy manual worker or pregnant woman

Answer 45

heavy manual worker

Question 46

who needs for calories per day: breast-feeding woman or pregnant woman

Answer 46

breast-feeding woman

Question 47

who needs for calories per day: heavy manual worker or breast-feeding woman

Answer 47

heavy manual worker

Question 48

how to measure the energy content of a food

Answer 48

• weigh the mass of a food sample
• place a measured amount of water in a boiling tube, clamp it on a base
• measure temp of water
• pierce the food on the end of a mounted needle and put it over a burning bunsen
• once its lit hold it under the test tube
• once completely burnt measure the new temperature of the water
• remember 4.2 joules of energy is the equivalent to 1 gram of water raised in temperature by 1 degree
• 1cm(cb) water has the mass of 1g
• use the equation to find the answer:
  energy in joules per gram =
  (final temp -start temp) x 20(g) x 4.2 (J per degree C) /mass of food (g)