Food And Energy 2020 Jan

Question 1

Starch test

Answer 1

Iodine solution

Yellow/brown to blue/black

Question 2

Sugar test

Answer 2

Benedicts solution
Heat water bath
Changes from blue to brick red precipitate

Question 3

Protein test

Answer 3

Biuret test 
Add sodium hydroxide 
Then add few drops of copper sulfate 
Shake 
Turns from blue to purple / lilac

Question 4

Fat test

Answer 4

Ethanol test
Shake the fat with ethanol then add water (equal amount)
Colourless ethanol changes to a cloudy white emulsion

Question 5

Carbohydrates (simple )

Answer 5

Simple carbohydrates are sugars such as glucose and lactose
Made up of one or 2 basic sugar units
Gd sources of energy

Question 6

Carbohydrates (complex )

Answer 6

Include starch, glycogen and cellulose

Made up of many glucose (sugar ) units linked together

Question 7

Carbohydrate

Answer 7

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

Question 8

Protein

Answer 8

Biological molecule formed of sub-units of amino acids.
Proteins can differ by containing different types or numbers of amino acids or by these being arranged in different sequences

Question 9

Fat

Answer 9

The basic sub-unit of a fat consists of one molecule of gycerol and 3 fatty acid molecules.
High in energy

Question 10

Energy released (equation)

Answer 10

En rel = mass of water (g) x temp rise x 4.2

By each gram of food === En rel = mass of water (g) x temp rise x 4.2 over mass of food (g)