Check your understanding 1. Describe two risks associated with this investigation.
[2 marks]
......................................................................................................................................................... ......................................................................................................................................................... 2. Match up each reagent to the nutrient it tests for.
[3 marks]
Benedict’s
lipid
biuret
protein
ethanol
glucose (a simple sugar)
iodine
starch (a complex carbohydrate)
3. This experiment required you to measure very small volumes of reagents. Suggest an appropriate piece of equipment you can use to measure very small volumes precisely.
[1 mark]
.........................................................................................................................................................
Exam-style questions 1. A student tested three foods using qualitative food tests. The results are shown in Table 3. Table 3 Observations
Food sample Starch test
Glucose test
Protein test
Lipid test
A
Brown
Blue
Purple
Milky white
B
Black
Brick red
Blue
Colourless
C
Brown
Brick red
Purple
Colourless
For each of the food samples, list the nutrients you can tell are present from the observations in Table 3. a. Food sample A
..................................................................................................
[1 mark]
b. Food sample B
..................................................................................................
[1 mark]
c. Food sample C
..................................................................................................
[1 mark]
2. Sudan III is a reagent that can also be used to test for lipids. If lipids are present, a thin red layer is present floating on top of the sample. Suggest a food that would provide a positive test result with Sudan III.
[1 mark]
......................................................................................................................................................... AQA GCSE (9–1) Combined Science: Trilogy Required Practicals Lab Book
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