Food groups

Question 1

What is a lipid

Answer 1

Fats and oils

Question 2

What’s the structure of a lipid

Answer 2

3 fatty acids, 1 glycerol

Question 3

Sources of lipids

Answer 3

Meat, cheese, eggs, seeds, peanut

Question 4

Functions of lipids

Answer 4

• Source of energy (and energy store)
• insulation (electrical for nerve cells and thermal beneath skin)
• form part of cell membrane
• cholesterol used to make steroid hormones

Question 5

What elements are found in lipids

Answer 5

Carbon, hydrogen, oxygen

Question 6

What elements are found in proteins

Answer 6

Carbon, hydrogen, oxygen, nitrogen, sulphur

Question 7

Structure of protein

Answer 7

A long chain of cells called amino acids. The sequence (order) of amino acids determines the shape of the protein molecule. It can be long and thin (eg keratin) or more spherical (eg haemogoblin)

Question 8

Sources of protein

Answer 8

Meat, fish, eggs, pulses, beans, soya bean

Question 9

Functions of proteins

Answer 9

• catalyst (enzymes)
• transport (haemogoblin)
• structural material (muscles)
• hormones (insulin)
• defence against natural diseases (antibodies)

Question 10

Give 2 examples of minerals

Answer 10

Iron, calcium

Question 11

Source of iron

Answer 11

Red meat, liver, some leafy vegetables

Question 12

Function of iron

Answer 12

Needed to produce haemogoblin for red blood cells

Question 13

What happens when you don’t get enough iron (deficiency)

Answer 13

Iron deficiency causes anaemia. The person feels weak as oxygen needed for respiration cannot be transported efficiently

Question 14

Sources of calcium

Answer 14

Milk, cheese, fish

Question 15

Functions of calcium

Answer 15

• production and growth of bones and teeth
• involved in the chemical reactions leading to the clotting of blood and
  the contraction of muscles

Question 16

What happens when you don’t get enough calcium (deficiency) ?

Answer 16

Calcium deficiency causes rickets (soft and bendy bones)

Question 17

Name 3 vitamins

Answer 17

vitamin A (eyes), vitamin D (bones), vitamin C (fibres)

Question 18

Sources of vitamin A

Answer 18

Liver, dairy, eggs

Question 19

Function of vitamin A

Answer 19

• used by cells in the retina to produce pigments
• essential for embryos to develop (tells cells where to go and what to
  become)
• used in the immune system to maintain integrity of skin and mucus
  cells in lining of breathing and digestive system

Question 20

What happens is you don’t get enough vitamin A

Answer 20

Vitamin A deficiency causes poor night vision

Question 21

Sources of vitamin D

Answer 21

Liver, dairy, eggs, fish oil, sunlight

Question 22

Function of vitamin D

Answer 22

Helps the body to absorb calcium

Question 23

What happens if you don’t get enough vitamin D

Answer 23

Vitamin D deficiency causes rickets (soft and bendy bones)

Question 24

Sources of vitamin C

Answer 24

Citrus fruits (lemon, lime, orange)

Question 25

Function of vitamin C

Answer 25

Helps cells sticking together in the lining of various organs (production of fibres holding cells together is affected)

Question 26

What happens when you don’t get enough vitamin C

Answer 26

Vitamin C deficiency causes gum problems (bleeding) and even scurvy (characterised by swollen bleeding gums and the opening of previously healed wounds)

Question 27

Why do we need water in our diets

Answer 27

Just about every bodily function requires water. We need a constant supply to replace water lost through urinating, breathing, and sweating

Question 28

Sources of water

Answer 28

All food and drink contains water

Water, watermelon, coconut water

Question 29

Sources of dietary fibre

Answer 29

Plant material (eg vegetables) contain indigestible fibres
Wholemeal bread

Question 30

Function of dietary fibre (roughage)

Answer 30

• Helps with digestion by providing bulk for gut contents (to be pushed
  along) and feces.
• prevents constipation.

Question 31

What is the test for glucose

Answer 31

The bennidicts test (solution is a test for all reducing sugars)

Question 32

Positive bennidicts test

Answer 32

Solution turns from blue to a brick-red colour and precipitate is formed

Question 33

Test for starch

Answer 33

Iodine

Question 34

Positive test for starch (iodine)

Answer 34

Iodine solution goes from yellow to a blue/black colour

Question 35

Energy released per gram (joules) =

Answer 35

Energy per gram = (mass of H2O) X (temperature rise *C) X 4.18

Question 36

How to find energy content in food sample

Answer 36

Measure 1g of foodstuff. Measure out a volume of water and take the temperature. Burn the foodstuff under the test tube until all that’s left is ash, measure the temperature rise.

Energy (J) = water mass X temp rise X 4.18

Question 37

How many joules in 1 calorie

Answer 37

1 calorie = 4200 j or 4.2Kj

Question 38

What is the function of carbohydrates

Answer 38

They are a good source of energy and are the main fuel of the body as glucose (respiration). It is also used to store starch, glycogen, and cellulose which provide structural support

Question 39

Sources of carbohydrates

Answer 39

Rice, wheat, barley

Question 40

What elements do proteins contain

Answer 40

Carbon, hydrogen, oxygen, nitrogen