Biological Molecules and Food Tests

Question 1

What are carbohydrates made from?

Answer 1

Simple sugars

Question 2

What elements do carbohydrate molecules contain?

Answer 2

Carbon, hydrogen and oxygen

Question 3

What are proteins made up of?

Answer 3

Amino acids

Question 4

What elements do protein molecules contain?

Answer 4

Carbon, nitrogen, hydrogen and oxygen

Question 5

What are lipids made up of?

Answer 5

Fatty acids and glycerol

Question 6

What elements do lipid molecules contain?

Answer 6

Carbon, hydrogen and oxygen

Question 7

How do you prepare a food sample?

Answer 7

1) Break up a piece of food
2) Transfer the food to a beaker and add distilled water
3) Stir the mixture to dissolve some of the food
4) Filter off excess food

Question 8

What do you use to test for glucose?

Answer 8

Benedicts solution

Question 9

What color will benedicts solution turn in low concentrations and high concentrations of glucose?

Answer 9

It will turn from blue to green/yellow in low concentrations.
It will turn blue to brick-red in high concentrations.

Question 10

How do you test for starch?

Answer 10

Iodine solution

Question 11

What color will iodine solution turn in starch?

Answer 11

Change from brown to black

Question 12

How do you test for proteins?

Answer 12

Biuret solution

Question 13

What color will biuret turn in proteins?

Answer 13

Change from blue to pink/purple

Question 14

How do you test for lipids?

Answer 14

Sudan III stain solution

Question 15

What color will Sudan III change to in lipids?

Answer 15

The top layer will turn bright red