1. 25/02/13
Plants and Photosynthesis

2. Things needed for photosynthesis
25/02/13
SUNLIGHT
Gives the plant energy
CHLOROPHYLL
The green
stuff
where the
WATER chemical
Travels up reactions
from the roots happen
CARBON DIOXIDE
Enters the leaf through small
holes on the underneath

3. Photosynthesis equations
25/02/13
Sunlight
Carbon dioxide + _____ glucose + _____
Chlorophyll
Sunlight
6CO2 + 6H20 C6H12O6 + 6O2
Chlorophyll
The GLUCOSE produced by photosynthesis is used by the
plant for _______ (through ____________). It is stored
in the plant as ___________.
Words – respiration, starch, water, oxygen, energy

4. 25/02/13
Photosynthesis happens in the
“palisade” cells in the leaf:
Palisade
cells

5. Close up on a palisade cell:
25/02/13
Cell
wall
Cell
Chloroplasts
membrane
(containing
chlorophyll)
Large
vacuole Nucleus
Cytoplasm

6. Method for starch test:
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1) Cover up part of the leaf using black card
What effect does this have on the plant?
2) Boil the leaf for a few minutes
What does this do to the leaf?
3) Soak the leaves in alcohol
What effect does this have on the leaf?
4) Dip the leaves in water
What effect does this have?
5) Drop some iodine onto the leaf
What do you see? Draw and explain your results

7. Results: 25/02/13
The parts of the leaf which have been photosynthesising
should have turned black.
This shows that the part of the leaf which was covered up
has not been photosynthesising, because it had no light.
NO LIGHT, NO PHOTOSYNTHESIS, NO STARCH!

8. Root hair cells 25/02/13
Plant roots are made of “root hair cells” which have two
features that help them to take in water and nutrients:
Root
hair
cells
Large surface area Thin cell membrane

9. Using water
25/02/13
Plants need water to do the following:
Produce
glucose
Enable
transport
of minerals
Form
fruits
Enable
Keep the
growth
leaves cool

10. Photosynthesis and Respiration
25/02/13
In earlier work we looked at respiration:
Glucose + oxygen water + carbon dioxide
Photosynthesis is the reverse of respiration:
Water + carbon dioxide glucose + oxygen