Nutrition And Food Tests

Question 1

How to test for reducing sugars?

Answer 1

Benedict’s reagent will turn from blue to green to orange and then produce a brick red precipitate when in contact with reducing sugars (end colour will depend on how much sugar is present). Heat will need to be added for this test.

Question 2

How to test for starch?

Answer 2

Iodine will change from yellow-brown to blue-black when in contact with starch

Question 3

How to test for protein?

Answer 3

Biuret reagent will change from blue to purple if protein is present. When conducting this test, it is important that you are careful with the reagent and you do not get it on your clothes or skin. This is because the reagent is made up of Sodium Hydroxide and Copper Sulfate

Question 4

How to test for fat?

Answer 4

Ethanol will change from colourless to produce a white emulsion when in contact with fats

Question 5

What is in protein that is not present in fats and carbohydrates?

Answer 5

Nitrogen

Question 6

What is present in carbohydrates, fats and proteins?

Answer 6

Carbon, hydrogen & oxygen

Question 7

What is the main function in the body for carbohydrates?

Answer 7

Energy store

Question 8

What is the main function in the body for fats?

Answer 8

Energy store

Question 9

What is the main function in the body for protein?

Answer 9

Growth and repair

Question 10

Define a balanced diet?

Answer 10

A diet that contains all the 7 main food ro ups in the right amount

Question 11

What are the 7 main food groups?

Answer 11

Carbohydrates
Fats/lipids
Protein
Vitamins
Minerals
Fibre
Water

Question 12

Describe a simple carbohydrate?

Answer 12

Exist as simple, single molecules (e.g. sugars, glucose & lactose)
Taste sweet
Soluble in water
Fast-acting energy source

Question 13

Describe a complex carbohydrate?

Answer 13

Made up of long chains of sugars joined together
Examples include:
Cellulose - very strong, used in plant cell walls
Starch - used by plants to store glucose (energy)
Glycogen - how animals & fungi store their glucose (energy)

Question 14

What does fats/lipids consist of?

Answer 14

3 fatty acids & 1 glycerol

Question 15

Describe proteins

Answer 15

Provide the building blocks for growth and repair of cells
Used for energy only when carbohydrates and fat are low
Consists of subunits called amino acids
There are 20 natural occurring amino acids
Examples of protein include: enzymes, haemoglobin and antibodies

Question 16

Why is it important to eat a balanced diet?

Answer 16

So we get a variety of nutrients for different functions in our body

Question 17

How does a person measure how much energy is released?

Answer 17

Energy released(J) = mass of water(g) X temp rise(Celsius) X 4.2