1. © OUP: To be used solely in purchaser’s school or college Food Tests Food Tests Review

2. © OUP: To be used solely in purchaser’s school or college Food Food Tests

3. © OUP: To be used solely in purchaser’s school or college What do we need food for? Energy to do things 8A Food – who needs it? Raw materials to grow larger Raw materials to repair damaged body parts

4. © OUP: To be used solely in purchaser’s school or college Proteins 8A So what’s in food? Food is a complicated mixture of different chemicals. We can sort these chemicals into different types. What are the main types? Fats Carbohydrates (starch and sugars) Vitamins Minerals Water Can you make up a sentence with words starting with the same letters – a mnemonic? Roughage

5. © OUP: To be used solely in purchaser’s school or college 8A Which food contains which chemical? Which foods belong to which food groups? ProteinsFatsCarbohydratesWater Proteins WaterCarbohydrates Fats

6. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? We can test foods to find out what chemicals they contain. Orangey-brown iodine turns blue-black when it reacts with starch. drop iodine solution onto the food black = starch

7. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? Blue Benedict’s solution turns orangey-red when it is boiled with glucose. blue turns orange/red = glucose heat chopped up food hot water

8. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? In the Biuret test the solution turns purple. chopped up food potassium hydroxide shake copper sulphate purple = protein

9. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? Fats go cloudy white when they are mixed with ethanol and water. Now see if you can use these tests to identify the food chemicals on the next slides. grind food with ethanol add water filter cloudy = fat

10. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? For each food, decide on the chemicals found in them. FatsProteinStarchGlucose Food sampleTestResult Iodine solutionorangey-brown Benedict’s testblue Biuret testpurple Ethanol testcloudy white

11. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? For each food, decide on the chemicals found in them. FatsProteinStarchGlucose Food sampleTestResult Iodine solutionblue-black Benedict’s testblue Biuret testblue Ethanol testclear

12. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? For each food, decide on the chemicals found in them. FatsProteinStarchGlucose Food sampleTestResult Iodine solutionorangey-brown Benedict’s testorangey-red Biuret testblue Ethanol testclear

13. © OUP: To be used solely in purchaser’s school or college 8A What’s in food? For each food, decide on the chemicals found in them. FatsProteinStarchGlucose Food sampleTestResult Iodine solutionorangey-brown Benedict’s testorangey-red Biuret testblue Ethanol testclear

14. © OUP: To be used solely in purchaser’s school or college 8A Vitamins VitaminFound inGives you A B2B2 C D Liver, butter, green vegetables Cheese, milk, liver, eggs, green vegetables Citrus fruits, green vegetables, potatoes Fish liver oil, eggs, sunlight on the skin Healthy skin and teeth Healthy skin Healthy teeth and gums, without it you get scurvy Healthy bones – without it you get rickets (soft bones)