1. LEAVES AND PHOTOSYNTHESIS

2. Wednesday 2nd May 2012
The Leaf
 I can state that leaves are adapted to photosynthesise efficiently
 I can describe the basic structure of a leave.

3. Some ways to improve my level
Read all the question and the paper.
Give the question some thought
Use correct key words as often as possible
Read the graph to the point do not round or approximate.

4. that green plants do not absorb ‘food’ from the soil
that green plants use carbon dioxide and water to produce their food
to represent photosynthesis by a word equation
What do plants need?
1. Sunlight – the plants source of energy 2. Chlorophyll – the green stuff which makes plants look green. 3. Water – travels up from the roots. 4. Carbon dioxide – diffuses in through the holes in the leaves. Do plants need oxygen?

5. that green plants do not absorb ‘food’ from the soil
that green plants use carbon dioxide and water to produce their food
to represent photosynthesis by a word equation
Question
What is the difference between respiration and photosynthesis?
Respiration video.

6. that green plants do not absorb ‘food’ from the soil
that green plants use carbon dioxide and water to produce their food
to represent photosynthesis by a word equation
Photosynthesis
Photosynthesis is the process where ________ make their own _______.
Plants make food which is in the form of g________e.
Plants need four things to be able to photosynthesise. They are _______ (from the roots), ______ (through the leaves), __________ (source of energy) and _________ (make plants look green).
The word equation for photosynthesis is:
____ _____ + _____  _______ + _______

8. Leaves work in a similar way to the solar cell
Leaves work in a similar way to the solar cell. They both need a lot of light energy to work. Photosynthesis takes place in the chloroplasts inside the leaf cells. Can you tell me the word equation for Photosynthesis?

9. Chloroplasts contain chlorophyll, a green pigment that takes in energy from the sunlight. All green parts of plants are able to photosynthesis because they contain chlorophyll. What are products of Photosynthesis?

11. Electron microscope image
Can you tell me why the leaf is not solid?

12. Structure of a leaf CUTICLE PALISADE LAYER SPONGY LAYER VEIN
AIR SPACES
STOMATA

13. How are palisade cells specialised?
Lots of chloroplasts, which contain chlorophyll to catch light energy.
Long and thin, so they pack closely together to collect as much light as possible.
They are at the top of the leaves, to get as much light as possible.

14. How does the carbon dioxide get inside the leaf?

15. Electron microscope image of the underside of a leaf.
Close up of a stoma on the under side of a leaf
What is this for?

16. Stoma is a small hole
Its size is controlled by 2 guard cells What is their function?
closed
open

17. Stoma function is for gas exchange in the leaf
oxygen
Guard cell
Provided plant is photosynthesising
Carbon dioxide

18. Key points
Leaves are usually very ……. so that sunlight and carbon dioxide can pass through easily
Broad, flat surface of a leaf ………… the surface area, allowing ……….. sunlight and carbon dioxide to reach cells
Stomata allow … ………. to diffuse into the leaf and oxygen to diffuse out of the leaf
Veins ……... water and minerals around the plant

19. Investigating photosynthesis – apparatus19

20. Investigating photosynthesis – experiment20

21. Investigating photosynthesis – results21