Small molecules are used as the basic units in the synthesis of large food molecules. Which statement is correct?
A Amino acids are basic units of carbohydrates.
B Fatty acids are basic units of glycogen.
C Glycerol is a basic unit of oils.
D Simple sugar is a basic unit of protein.
When a substance is added to meat, amino acids are produced.
What is this substance?
A a hormone
B an enzyme
C an oil
D water
The diagram shows part of a protein molecule.
What does X represent?
A amino acid
B fatty acid
C glycerol
D sugar
Four different foods were tested for their composition. The results are shown in the table.
Which food contains protein but not reducing sugar or starch?
A
B
C
D
What are the smaller basic units of starch and glycogen molecules?
The diagram represents a protein molecule.
What do the small circles represent?
A amino acids
B fatty acids
D simple sugars
Which row shows the elements and basic units that are used in the construction of large food molecules
Which nutrient produces a purple colour when mixed with biuret solution?
A fat
B protein
C reducing sugar
D starch
Which food-testing reagent shows a positive result when it turns from blue to purple?
A Benedict’s solution
B biuret reagent
C ethanol
D iodine solution
The diagram shows two food tests carried out on solution X.
Which nutrients are present in solution X?
A protein and starch
B protein and sugar
C starch and fat
D starch and sugar
The data show the concentrations of sugar and starch in an onion. The onion is tested with Benedict’s solution and iodine solution.
Which set of results is correct?
A Benedict’s solution = blue; iodine solution = blue-black
B Benedict’s solution = blue; iodine solution = brown
C Benedict’s solution = brick red; iodine solution = blue-black
D Benedict’s solution = brick red; iodine solution = brown
A human cell contains a length of DNA that carries the code for making which substance?
B glycogen
C lipase
A student set up a test-tube containing starch, water and amylase.
How could the student test whether the amylase had digested all the starch?
A Add Biuret solution.
B Add dilute hydrochloric acid.
C Add iodine solution.
D Weigh the test-tubes and contents before and after the experiment.
When solution X is tested with iodine solution, a blue-black colour is observed. A different solution, Y, is added to a new sample of solution X and the mixture is shaken and left for 30 minutes at 40 °C. When tested with iodine solution, an orange-brown colour is observed.
What are solutions X and Y?
A X = maltose; Y = amylase
B X = maltose; Y = lipase
C X = starch; Y = amylase
D X = starch; Y = lipase
Which row correctly identifies the chemical elements found in proteins?
The top diagram shows part of a starch molecule.
Which diagram shows this molecule after it has been completely digested?
Four foods were tested for: * fat (using ethanol), * protein (using the biuret test), * reducing sugar (using Benedict’s solution), * starch (using iodine solution).
Which food contains protein and starch?
Which elements do carbohydrates contain?
A carbon, hydrogen and oxygen only
B carbon, hydrogen and sulfur only
C carbon, nitrogen and oxygen only
D carbon, nitrogen and sulfur only
What does the digestion of starch produce?
A fatty acids
B glucose
C mineral salts
The diagram shows part of a starch molecule.
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