Biology food tests

Question 1

Why do we do food tests?

Answer 1

To test for concentration and presence of carbohydrase, proteins and lipids.

Question 2

What colour is Benedict’s reagent?

Answer 2

Blue liquid

Question 3

What colour does Benedict’s reagent turn when sugars are present?

Answer 3

Green, yellow, orange, red

Question 4

What does Benedict’s test identify?

Answer 4

Sugars

Question 5

How do we test for sugars after applying Benedict’s reagent?

Answer 5

Heat the food up

Question 6

What colour is Iodine solution?

Answer 6

Brown

Question 7

What colour will Iodine turn if starch is present?

Answer 7

Black

Question 8

What does the iodine test identify?

Answer 8

Starch

Question 9

What happens when starch is present in food?

Answer 9

Iodine will bind and turn black

Question 10

What colour is Biuret reagent?

Answer 10

Blue

Question 11

What colour will Biuret reagent turn if proteins are present?

Answer 11

Purple shade

Question 12

What does the Biuret test identify?

Answer 12

Proteins

Question 13

How do we test for osmosis?

Answer 13

Potato test

Question 14

Name the steps of the potato test

Answer 14

Cut potato into identical pieces, measure mass of potatoes and record, put into tub with different concentrations of sugar or salt into water, leave the potatoes for a while, dry off potato slices and weigh them again, calculate the mass gained or lost during the experiment

Question 15

Why do we use potatoes for osmosis tests?

Answer 15

Potato cells are semi permeable allowing water to be passed but not solutes