🥞 Food and Energy 🏃‍♀️

Question 1

Starch test

Answer 1

iodine solution.

Question 2

Colour change starch

Answer 2

• iodine
• yellow-brown blue-black.

Question 3

Sugar test

Answer 3

Benedict’s reagent

Question 4

Sugar colour change

Answer 4

Blue to brick-red precipitate.

Question 5

Benedict’s method

Answer 5

Add Benedict’s solution and heat in a water bath.

Question 6

Protein test

Answer 6

• add sodium hydroxide, then a few drops of copper sulfate and shake
• biuret test

Question 7

Protein colour change

Answer 7

• biuret test
• blue —-> purple/ lilac

Question 8

Fat test method

Answer 8

Shake the fat with ethanol (alcohol), then add an equal amount of water

Question 9

Fat test colour change

Answer 9

• ethanol
• Colourless —> cloudy white emulsion

Question 10

Biological molecules

Answer 10

• carbs
• proteins
• fats

Question 11

What do biological molecules contain?

Answer 11

• carbon
• hydrogen
• oxygen
• nitrogen (protein)

Question 12

“Simple” carbohydrates

Answer 12

sugars such as glucose and lactose - they are described as ‘simple’ as they are made up of one (e.g. glucose) or two (e.g. lactose) basic sugar units

Question 13

Glucose use

Answer 13

Glucose is the sugar that is normally used in respiration.

Question 14

Carbohydrate

Answer 14

biological molecule formed of sugar sub-units
- Carbohydrates differ by having different numbers or types of sugar sub-unit.

Question 15

Lactose use

Answer 15

Lactose is the sugar and energy source in milk

Question 16

Sugars

Answer 16

Sugars are ‘fast-release’ energy stores

Question 17

What can sugars be

Answer 17

quickly metabolised to release energy

Question 18

Complex carbohydrates

Answer 18

• starch, glycogen and cellulose
• made up of many glucose (sugar) units linked together

Question 19

What are starch and glycogen important for?

Answer 19

Storage molecules

Question 20

main storage molecule in plants

Answer 20

Starch

Question 21

main storage molecule for animals

Answer 21

Glycogen
- liver
- muscles

Question 22

Structural carbohydrate

Answer 22

Cellulose
- provides support plant cell walls

Question 23

What does cellulose do?

Answer 23

Provides support in cell walls

Question 24

Protein

Answer 24

• biological molecule formed of subunits of amino acids
• can differ by:
• containing different types
• numbers of amino acids
• these being arranged in different sequences

Question 25

1g water = ?

Answer 25

1cm3 water

Question 26

How can proteins differ?

Answer 26

• dif. link arrangements
• structural (e.g. muscle)
• functional (e.g. enzymes, antibodies)

Question 27

Sources of protein

Answer 27

• lean meats
• lentils
• fish

Question 28

Fat

Answer 28

the basic unit of a fat is glycerol and three fatty acids

Question 29

Why are fats excellent storage molecules?

Answer 29

high in energy (1g of fat contains approximately twice as much energy as 1g of carbohydrate or protein)

Question 30

What does too much fat in the diet cause?

Answer 30

Health problems

Question 31

What are lipids?

Answer 31

What fats are also called

Question 32

food-energy test results (fair test)

Answer 32

When comparing diff. foods:
- use same amount food
- hold burning food same distance from boiling tube

Question 33

Food-energy test, where does energy go?

Answer 33

• lost in air
• lost heat glass
• left in burned food remains

Question 34

Food-energy test equation

Answer 34

Energy released in J = water mass (g) x rise in temp. x 4.2