Biology Food Tests Quiz

What is the test for glucose (a reducing sugar)?

• Food sample is mixed with 2cm3 of ethanol and shaken

• Add drops of Biuret solution to the food sample

• Add drops of iodine solution to the food sample

• Add Benedict's solution into sample in a test tube and heat at 60 - 70 °c in water bath for 5 minutes

How can we test for the presence or absence of starch in a food sample?

• Food sample is mixed with 2cm3 of ethanol and shaken

• Add drops of Biuret solution to the food sample

• Add drops of iodine solution to the food sample

• Add Benedict's solution into sample solution in test tube and heat at 60 - 70 °c in water bath for 5 minutes

What is the test for protein?

• Add Benedict's solution into sample solution in test tube and heat at 60 - 70 °c in water bath for 5 minutes

• Add drops of iodine solution to the food sample

• Add drops of Biuret solution to the food sample

• Food sample is mixed with 2cm3 of ethanol and shaken

How can we test for lipids in a food sample?

• Add drops of iodine solution to the food sample

• Add Benedict's solution into sample solution in test tube and heat at 60 - 70 °c in water bath for 5 minutes

• Food sample is mixed with 2cm3 of ethanol and shaken, then water is added

• Add drops of Biuret solution to the food sample

What should be observed for a positive Benedict's test for glucose?

• Colour change from orange-brown to blue-black

• Colour change from blue to violet / purple

• Colour change from blue to orange or brick red

• Cloudy emulsion forming

What should be observed for a positive iodine test for starch?

• Colour change from orange-brown to blue-black

• Colour change from blue to orange or brick red

• Colour change from blue to violet / purple

• Cloudy emulsion forming

What should be observed for a positive Biuret test for protein?

• Colour change from orange-brown to blue-black

• Colour change from blue to orange or brick red

• Colour change from blue to violet / purple

• Cloudy emulsion forming

What should be observed for a positive ethanol test for lipids?

• Colour change from orange-brown to blue-black

• Colour change from blue to orange or brick red

• Colour change from blue to violet / purple

• Cloudy emulsion forming

What are carbohydrates mainly used for in the body?

Lipids help animals to stay _______ in water.