Food Tests

Question 0

What are the elements present in proteins?

Answer 0

Carbon, hydrogen, oxygen and nitrogen

Question 1

How do we test for protein?

Answer 1

Using Buiret reagent {copper sulphate + sodium hydroxide}

Question 2

How many types of amino acids are there?

Answer 2

20 different ones

Question 3

What can amino acids do?

Answer 3

Join up in chains to make protein molecules

Question 4

What happens when you test for protein?

Answer 4

The colour will change from light blue to purple

Question 5

What are the elements present in carbohydrates?

Answer 5

Carbon, hydrogen and oxygen

Question 6

What is an example of monosaccharide?

Answer 6

Glucose

Question 7

What is an example of a polysaccharide?

Answer 7

Starch

Question 8

How can we test for glucose?

Answer 8

Using Benedict reagent which turns from blue to brick red if glucose is present.

Question 9

How can we test for starch?

Answer 9

Using iodine, which turns from orange to dark blue/ black.

Question 10

What are the elements present in lipids?

Answer 10

Carbon, hydrogen and oxygen

Question 11

What state are fats in at room temperature?

Answer 11

Solid

Question 12

What state are oils in at room temperature?

Answer 12

Liquid

Question 13

What are lipids made of?

Answer 13

1 glycerol molecule

3 fatty acids

Question 14

How can we test for lipids?

Answer 14

We can test for lipids using the emulsion test. When ethanol is mixed with lipids and water the solution turns cloudy.

Question 15

What is the alternative test that we can use for lipids?

Answer 15

The brown paper test: if lipids are present, the paper will be absorbed.

Question 16

How can we test for vitamin c?

Answer 16

We can use DCPIP which turns from blue to colourless if vitamin c is present.