1. Leaf Challenge! Cell wall Nucleus Chloroplast Cell membrane Vacuole
Cytoplasm Chlorophyll Stoma
Upper epidermis Waxy cuticle
Mesophyll Air space
Lower epidermis Guard cell with chloroplast
Palisade mesophyll Waxy cuticle
Spongy mesophyll

3. Palisade Cell

5. Palisade Cell

6. Testing For Starch Lesson Objectives
C/W
Date………………………..
Testing For Starch
Lesson Objectives
To describe how plants store excess glucose as starch.
To be able to test for starch in leaves.
Success Criteria
Starch is stored in the leaves
Describe the test for starch in leaves

7. Key Challenge!
What we need for photosynthesis? What is the pigment that captures the sunlight? What do we make in the process of photosynthesis?
Photosynthesis song – You tube

8. What is photosynthesis?
light energy
chlorophyll
carbon dioxide + 
water
oxygen
glucose
What is the symbol equation for this reaction?
light energy 6
CO2 + 6
H2O + 
C6H12O2 6 O2
chlorophyll
Is this a balanced symbol equation?
How would you balance the equation?

9. glucose What do plants with the glucose made by photosynthesis?
Some glucose is used straight away in respiration. Plants also carry out respiration to
release the energy they need for life processes.
glucose
Some glucose is converted into starch and other
substances for storage. These stores of energy
can be used later when the plant needs them.
Some glucose is used to make new chemicals
such as proteins, sugars and fats that the plant
also needs to function properly.

10. A plant will store excess the GLUCOSE as starch once it has been made.
We can test whether the leaf has photosynthesised or not by testing the leaf for starch.
Lets get practical!!

11. Aim:Test whether the leaf has photosynthesised or not by testing the leaf for starch.2
Ethanol
Boiling Water
Testing 2 leaves: one that has been in the light and one that has been in the dark. Cut the end off the leaf that has been in the dark.
Place both leaves (in light and one in dark) in a beaker of boiling water = 1 minute with forceps.
Half fill a boiling tube with ethanol. Place both leaves in test tube of ethanol and stand for 8 to 10 minutes. – Place it in the beaker to support the boiling tube.
Complete the following while waiting: Aim,Diagram,Method

12. Starch is only made in a leaf when photosynthesis has happened!!
Aim:Test whether the leaf has photosynthesised or not by testing the leaf for starch.
4. Remove both leaves with forceps and wash with tap water.
5. Place both leaves in petri dish and add 5 drops of iodine solution to each leaf. Leave for 2 mins.
5. Starch present = Blue/Black colour !
Starch is only made in a leaf when photosynthesis has happened!!

13. Answer questions 1 to 5 on the worksheet ‘Testing a leaf with starch’
Aim, Method, Diagram
Conclusion:
What have you found out?
Describe what colour the leaf turned.
Why did the leaf turn this colour?
How could you have improved your experiment?
Extension:
Answer questions 1 to 5 on the worksheet ‘Testing a leaf with starch’

14. glucose What do plants with the glucose made by photosynthesis?
Some glucose is used straight away in respiration. Plants also carry out respiration to
release the energy they need for life processes.
glucose
Some glucose is converted into starch and other
substances for storage. These stores of energy
can be used later when the plant needs them.
Some glucose is used to make new chemicals
such as proteins, sugars and fats that the plant
also needs to function properly.

15. What is photosynthesis?
light energy
chlorophyll
carbon dioxide + 
water
oxygen
glucose
What is the symbol equation for this reaction?
light energy 6
CO2 + 6
H2O + 
C6H12O2 6 O2
chlorophyll
Is this a balanced symbol equation?
How would you balance the equation?

16. Key Questions
How do we know that oxygen is produced during photosynthesis?
How can we measure the rate of photosynthesis?
What are dependent and independent variables?

17. Oxygen relights a glowing splint
Test for Oxygen
Oxygen relights a glowing splint

18. HOT SEAT! Volunteer needed.
You can only ask questions with a Yes or No answer.
Am I furry? Am I large?

19. Chloroplasts

20. stomata

21. Limiting Factors

22. Sunlight

23. Carbon dioxide

24. Temperature

25. Glucose

26. Leaf

27. Anagrams