Biological Molecules Food Tests

Question 1

what is the test for glucose?

Answer 1

benedict’s solution

Question 2

method for benedict’s food test?

Answer 2

• add benedict’s solution to a sample of food (in solution)
• place in a water bath at 80 degrees for 5 minutes

Question 3

method for benedict’s food test?

Answer 3

• add benedict’s solution to a sample of food (in solution)
• place in a water bath at 80 degrees for 5 minutes

Question 4

what is a positive result for glucose?

Answer 4

blue -> brick red

Question 5

what is the food test for starch?

Answer 5

iodine

Question 6

method for iodine food test?

Answer 6

• add a few drops of orange iodine solution to the sample on a spotting tile

Question 7

what is a positive result for starch?

Answer 7

orange -> blue/black

Question 8

what is the food test for protein?

Answer 8

biuret’s

Question 9

method for biurets food test?

Answer 9

• add 2cm3 water to a food sample and shake (if not already liquid)
• add an equal volume of dilute potassium hydroxide and shake
• add two drops of 1% copper sulphate solution

Question 10

what is the food test for lipids?

Answer 10

ethanol emulsion test

Question 11

method for emulsion test?

Answer 11

• place a food sample in a test tube
• add a small volume of absolute ethanol and shake to dissolve any lipid in the alcohol
• add an equal volume of water

Question 12

what is a positive result for lipids?

Answer 12

colourless -> milky white