Food tests: practical
Lesson details
Learning outcome
I can carry out tests for nutrients and some of the substances they are broken down into.
Key learning points
- Chemical reagents can be used to test for large food molecules including protein, fat, and carbohydrates such as starch.
- Chemical reagents can be used to test for smaller food molecules, such as sugars from the breakdown of starch.
- Interpretation of qualitative food test results.
Keywords
Food test - A food test shows if a specific type of food is present in a sample.
Reagent - A reagent is a chemical used to test for a type of food.
Qualitative - A qualitative test is one that gives an indication of presence, but not an exact figure.
Quantitative - A quantitative test is one that gives a measurable, numerical, value.
Common misconception
Confusing the reagents and the substances they test for, or the results of the tests.
Each test is dealt with separately and the positive and negative results are discussed sequentially.
Teacher tip
In the third learning cycle, consider having some physical examples of quantitative tests to hand as described in the lesson.
Equipment
pestle & mortar, distilled water, white tile, iodine & Benedict's solutions, boiling tube water bath
Content guidance
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.True or false? Food is broken down into nutrients by both mechanical and chemical digestion.
Q2.Match the food to the nutrient it is broken down into.
Fish
Butter
Potato
Q3.Which organ makes bile to help breakdown fats?
Q4.Put these in order to show the path of food through the body.
Q5.True of false? Enzymes are chemicals that are used up during the chemical breakdown of food.
Q6.Match the type of enzyme to the nutrient that is released.
Amino acids
Glycerol and fatty acids
Sugars
Assessment exit quiz
6 Questions
Q1.What is a food test?
Q2.Match the food test to its results.
the iodine will turn blue/black in colour.
the iodine will stay red/brown in colour.
the Benedict's solution will change colour.
the Benedict's solution will stay blue.
Q3.Put the method for testing if reducing sugars are present, in the right order.
Q4.Starting with the least, put these foods in order of the amount of reducing sugars they contain.
Q5.What does this result tell us about the food being tested?
Q6.Both iodine and Benedict’s solution give an indication of the presence or absence of a food, but not a quantitative result, we call this a result.
To help you plan your 8 science lesson on: Food tests: practical, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 8 science lesson on: Food tests: practical, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 science lessons from the Human digestive system unit, dive into the full secondary science curriculum, or learn more about lesson planning.