1. What do we need to digest our food?
L.I: To understand the major food groups our bodies need to digest and to carry out food tests
THINK:
What is digestion?
What do we need to digest our food?

2. The digestive system
Food must be digested before our bodies can use it.
DIGESTION means breaking down large, insoluble molecules of food into smaller, soluble molecules. This takes place in our digestive system, which runs from the mouth to the anus.

3. Carbohydrates - are energy foods Fats – store energy
Proteins – used for growth and repair
Vitamins & Minerals – keep our bodies healthy
Fibre – keeps food moving through our system

4. Substance Chemical test Result Sugar Solution Starch Solution
When the Benedict's reagent was placed in the sugar solution and heated it turned _____.
Starch Solution
When the Iodine was placed into the starch solution it turned _____ ______.
Protein solution
When the Biuret solution was placed into the protein solution it turned ________.
Fat – Method 1
When the butter was rubbed on the filter paper, the paper became translucent as a ______ _____ appeared on the paper.
Fat – Method 2
When the cheese was placed into the water and ethanol solution, the test tube became _____.
Benedict’s solution
Iodine
Biuret
Solution
Translucent Fat Test
Water and Ethanol

5. Testing for Starch
You will need: iodine solution, starch solution, test tube and a test tube rack .
Fill one quarter (¼) of a test tube with starch solution.
Add a few (3- 4) drops of iodine into the test tube. (WARNING: THIS MAY STAIN SO AVOID SPILLAGES)
Record on your worksheet using the words provided what colour the solution in the test tube turns.
Pour the iodine down the sink. Wash away any excess black liquid that is in the sink as it will stain.

6. Testing for Protein
You will need: Biuret solution, protein solution, test tube and a test tube rack .
Fill one quarter (¼) of a test tube with protein solution.
Add a few drops (3 - 4) of Biuret solution into the test tube. (WARNING: THIS MAY STAIN).
Shake the test tube and leave for 2 minutes.
Record on your worksheet using the words provided what colour the solution in the test tube turns.

7. Fat method 1 – Translucent spot test
You will need: 1 sheet of filter paper, 1 small cube of butter and 1 paper towel
Collect the butter in a paper towel using a spatula and bring back to your desk.
Using your fingers, rub the butter into the filter paper.
Hold the paper up the light, and record on your worksheet in your table what has happened to the paper.

8. Substance Chemical test Result Sugar Solution Starch Solution
When the Benedict's reagent was placed in the sugar solution and heated it turned _____.
Starch Solution
When the Iodine was placed into the starch solution it turned _____ ______.
Protein solution
When the Biuret solution was placed into the protein solution it turned ________.
Fat – Method 1
When the butter was rubbed on the filter paper, the paper became translucent as a ______ _____ appeared on the paper.
Fat – Method 2
When the cheese was placed into the water and ethanol solution, the test tube became _____.
Benedict’s solution
orange
Iodine
blue
black
Biuret
Solution
lilac
Translucent Fat Test
clear spot
Water and Ethanol
cloudy

9. 4 food samples were tested can you identify what food group they belong too?
IODINE
BIRUET SOLUTION
BENEDICT’S SOLUTION
TRANSLUCENT SPOT TEST
WATER & ETHANOL A B C D

10. Can you identify the food group?
Sample A could contain __________ because Iodine test showed positive results.
Sample B could contain __________ because the Benedict’s reagent shows positive results.
Sample C could contain__________ because the Biuret solution showed positive results.
Sample D could contain __________ because both the translucent and water and ethanol test showed positive results.
starch
sugar
protein
fat

11. What you have learnt today.
I can name the major food groups and explain why we need them.
I know the tests used to carry out food tests.