How to play Food Tests Lab
Food Tests Lab is a free GCSE biology game about food tests. You match each test to the food substance it finds. The game uses four tests: Benedict's solution, iodine solution, Biuret reagent and the emulsion test. Each question shows a test or a substance. You pick your answer from the buttons below it, or press 1 to 4 on a keyboard.
A game has ten questions. The first four ask which substance each test finds, and each gives you three answers to choose from. Next you pick the colour of a positive result for two of the tests. Then you say which test needs a water bath. The last three questions turn things round. You see a substance and pick the test that finds it.
Tick the harder start to begin with the colours and the water bath. With the harder start, every matching question gives you four answers.
Each right answer scores 10 points. A 30-second clock runs on every question. If it reaches zero, the question counts as wrong. The practice switch turns the clock off. After each answer, a short line shows the right match. Your best score stays on this device, and the harder start keeps a best score of its own.
The science behind food tests
A food test checks whether a food contains one type of substance. You add a chemical, called a reagent, to a sample of the food. If the substance is there, you get a positive result. For two of the tests, a positive result is a clear colour.
Benedict's solution tests for sugars. Edexcel says it finds reducing sugars and that you need a water bath for it. A positive Benedict's test is brick red. Iodine solution tests for starch. Biuret reagent tests for protein, and a positive result is purple. Edexcel describes the Biuret test in two steps. First you add potassium hydroxide to a solution of the food, then copper sulfate. The emulsion test finds fats and oils. Fats and oils are also called lipids.
The tests link to digestion. Digestive enzymes turn food into small molecules that dissolve and pass into the blood. Carbohydrases break carbohydrates down into simple sugars. Amylase is one of them, and it breaks down starch. Proteases break proteins into amino acids. Lipases break lipids into glycerol and fatty acids. In AQA's pH practical, you test for starch with iodine every 30 seconds. This times how long amylase takes to digest all the starch.
AQA covers the tests in Required Practical 4 of Biology 8461 and Required Practical 3 of Combined Science 8464 (section 4.2.2.1). Both name Benedict's, iodine and Biuret. They ask you to test for carbohydrates, lipids and proteins, but they do not name the emulsion test. Edexcel Biology 1BI0 has all four tests in core practical 1.13B. Edexcel Combined Science 1SC0 has no food tests practical like this one. It uses iodine for starch only, inside its pH and enzyme practical (1.10). OCR J247 lists the testing of biological molecules as practical group B2, linked to B1.3d to B1.3f. In OCR J257, using tests for biological molecules is a learning outcome in B4.1, with a practical (PAG2). Neither OCR course names the reagents.
Tips for remembering the food tests
- Learn the two colours first. Brick red goes with Benedict's and sugars. Purple goes with Biuret and protein.
- Purple and protein both start with a p. That keeps the two colours from swapping.
- Iodine goes with starch. AQA's enzyme practical uses the same test.
- The emulsion test finds fats and oils. Edexcel names this test, but AQA does not.
- Only Benedict's uses the water bath. If a question mentions heating, think of sugars.
A wrong answer or a timeout sets your streak back to zero. With the clock off, say each answer out loud before you tap.
Use this in the classroom
Food Tests Lab suits Years 9 to 11. Use it the lesson before the food tests practical, or as a check after it. A full game takes about five minutes.
Before the practical, put the first four questions on the board. Ask the class to write each match on a mini whiteboard before anyone taps. After the practical, play the colour questions. Ask students to compare the colours with what they saw in their own tubes. The water bath question opens a short talk about heating safely in the lab. To finish, name a food and ask which test would show whether it contains protein, and what colour a positive result would be.
AQA does not name the emulsion test, so treat those questions as extra for AQA classes. If you teach Edexcel Combined Science, tell students that only the iodine test for starch is on their course.
The practice switch removes the clock for students who want more thinking time. No one signs up or logs in to play. Our teachers page has more lesson ideas, and the what we collect page sets out what the site records.
Similar games
Once you can find sugar in a food, see what cells do with glucose in Respiration Equations. Photosynthesis Lab shows how plants make glucose in the first place. Digested food passes into the blood, and Heart and Circulation follows that blood round the body. The biology games page lists the rest.
Questions about food tests
Short answers to what students and teachers ask most about food tests.
What are the four food tests in GCSE biology?
Benedict's solution tests for sugars, iodine solution for starch and Biuret reagent for protein. The emulsion test finds fats and oils. AQA names the first three tests, and Edexcel Biology names all four.
What colour is a positive Benedict's test?
Brick red. Students often mix this up with the Biuret test for protein, where a positive result is purple.
Is the food tests practical the same on every exam board?
No. AQA sets it as a required practical in both Biology and Combined Science. Edexcel Biology has all four tests in core practical 1.13B. Edexcel Combined Science only uses iodine to test for starch, as part of its enzyme and pH practical.
Which food test needs a water bath?
The Benedict's test for sugars. Edexcel's core practical names a water bath for this test and for none of the other three.