Ch 4 Nutrients

Which substance is built up from amino acids?

• glucose

• glycogen

• protein

• urea

A food is known to contain reducing sugar and protein.

When this food is tested for reducing sugar and proteins what would a student observe?

• Benedict's test: blue

  Biuret test:

  blue

• Benedict's test: blue

  Biuret test:

  purple

• Benedict's test: brick-red precipitate

  Biuret test:

  blue

• Benedict's test: brick-red precipitate

  Biuret test:

  purple

Benedict's solution is used to test for the presence of reducing sugars. Which colour change shows the presence of reducing sugar?

• blue to brick-red

• blue to purple

• brick-red to blue

• purple to blue

Water has a number of roles in living organisms. What is a role of water?

• buoyancy

• energy source

• insulation

• transport

Which basic units are used to synthesise proteins?

• amino acid

• fatty acids

• glucose

• glycerol

Which chemical is used to test for the presence of protein in a food sample?

• Benedict's solution

• biuret solution

• ethanol and water

• iodine

A sample of food contains reducing sugar and fat. Which food test results show this?

• Biuret solution turns purple and iodine solution blue-black

• Brick red precipitate formed in Benedict's solution and biuret solution turns purple.

• Brick red precipitate formed with Benedict's solution and cloudy white emulsion formed with ethanol and water.

• Iodine solution turns blue-black and white emulsion formed with ethanol and water.

Name the element present only in proteins but not carbohydrates and fats.

What are fats (lipids) synthesised from?

• amino acids and fatty acids

• fatty acids and glycerol

• glucose and amino acids

• glycerol and glycogen

Which is not a reducing sugar?

• glucose

• sucrose

• fructose

• maltose