January Exam

Question 1

What chemical is needed to test for starch

Answer 1

Iodine

Question 2

What chemical is needed to test for sugar

Answer 2

Benedict’s solution

Question 3

What chemical is needed to test for protein

Answer 3

Sodium hydroxide + copper sulfate (biuret solution )

Question 4

What chemical is needed to test for fat

Answer 4

Ethanol

Question 5

What is the initial colour of starch and what does it change to

Answer 5

Yellow - brown to blue - black

Question 6

What is the initial colour of sugar and what does it change to

Answer 6

Blue to green&raquo_space; brick - red

Question 7

What is the initial colour of protein and what does it change to

Answer 7

Blue to purple / lilac

Question 8

What is the initial colour of fat and what does it change to

Answer 8

Clear to white emulsion

Question 9

What are the 7 main food groups

Answer 9

Water
Carbohydrates
Protein
Fat
Minerals
Dietary fibre
Vitamins

Question 10

What is the function of carbohydrates

Answer 10

Energy source

Question 11

What is the function of protein

Answer 11

Growth + repair of cells

Question 12

What is the function of fat

Answer 12

Energy, insulation + protection of body organs

Question 13

What is the function of vitamin C

Answer 13

Healthy cells and helps prevent diseases

Question 14

What is the function of vitamin D

Answer 14

Strong bones + teeth

Question 15

What is the function of calcium

Answer 15

Strong bones + teeth

Question 16

What is the function of iron

Answer 16

Helps make red blood cells to carry oxygen around the body

Question 17

What is the function of fibre

Answer 17

Prevents constipation

Question 18

What is the function of water

Answer 18

Stops us becoming dehydrated (chemical reactions etc.)

Question 19

How do you work out energy

Answer 19

Energy in 1g of food = rise in temperature x volume of water x 4.2

Question 20

Why might energy on the label be higher on the food label then in the experiment

Answer 20

Heat lost to the atmosphere
Heat lost in apparatus
Water may have not been stirred

Question 21

What is the ‘equation’ for tooth decay

Answer 21

Bacteria + sugar&raquo_space; acid + time&raquo_space; tooth decay

Question 22

What is the value of critical pH

Answer 22

5.5

Question 23

Food is taken into the body

Answer 23

Ingestion

Question 24

Food is broken down into soluble substances

Answer 24

Digestion

Question 25

The soluble products are absorbed into the bloodstream and transported round the body

Answer 25

Absorption

Question 26

The soluble products of digestion are taken into the cells where they are used

Answer 26

Assimulation

Question 27

Removal of waste (faeces)

Answer 27

Egestion

Question 28

What is mechanical digestion

Answer 28

Happens in the mouth As our teeth cut and grind food into smaller pieces. This increases the surface area. This also happens in the stomach as it’s muscular walls churn the food

Question 29

What is chemical digestion

Answer 29

Involves breaking the large molecules into smaller ones. Enzymes speed up chemical reactions and therefore are responsible for chemical digestion

Question 30

What are the 3 main enzymes

Answer 30

Amylase
Protease
Lipase

Question 31

Where are the 3 main enzymes found

Answer 31

Amylase - mouth, pancreas + small intestine
Protease - stomach, pancreas + small intestine
Lipase - pancreas + small intestine

Question 32

What food group do the 3 main enzymes work on and what do they turn into after digestion

Answer 32

Amylase- starch - sugar molecules
Protease - protein - amino acids molecules
Lipase - fat - fatty acid + glycerol

Question 33

What is the word equation for respiration

Answer 33

Glucose + oxygen&raquo_space; carbon dioxide + water + energy