1. Photosynthesis
4.3

2. Chloroplasts Are found in plant cells
Mostly within palisade mesophyll cells
Chloroplasts work as transducers by converting inorganic CO2 into carbohydrates (glucose)

3. On whiteboards in pairs draw and label a chloroplast

4. C B A D E F

6. The Chloroplast Has a double membrane Is filled with the stroma
Has Thylakoids – stacked together called grana
Spaces inside the thylakoids are connected together forming the thylakoid space
Acts as a transducer – converts light energy to chemical energy in the form of ATP

7. Different stages of photosynthesis take place in different regions of the chloroplast

8. Light Harvesting
Photosynthetic pigments trap light energy
Chlorophyll a
Chlorophyll b
Carotenoids – Xanthophyll and carotene
They are arranged in clusters in the thylakoid membrane – the antenna complex
Their arrangement ensures maximum light harvesting

10. Antenna Complex The arrangement funnels light to chlorophyll a
Chlorophyll a is the reaction centre
The other pigments are accessory pigments
Reaction centre + accessory pigments = photosystem

11. Position of the Photosystem in the thylakoid membrane

12. Wavelengths of light Light photons travel in waves
Each colour of light has a different wavelength (nm)
All the colours combine to form white light

13. Wavelength of light Not all light is used by the chlorophyll Reflected
Transmitted

14. Absorption Spectrum Shows which light is absorbed by each pigment
No pigment absorbs green-yellow
Hence plants look green

15. Action Spectrum Shows the rate of photosynthesis at each wavelength
Most photosynthesis where most light is absorbed
Measure O2 production to indicate rate of photosynthesis

16. Chromatography

17. Questions to check your understanding
Page 15 Q 1- 10

18. Photosystems There are two types of photosystem
Each absorbs light at a different wavelength
Photosystem II – P680 , absorbs light at 680nm(orange-red light)
Photosystem I – P700, absorbs light at 700nm(red light)

20. Biochemistry of Photosynthesis
Light dependent stage
Light independent stage

21. Photosynthesis A series of biochemical pathways In the chloroplast
Light dependent stage – thylakoid membrane
Cyclic and non-cyclic photophosphorylation
Light independent stage - stroma

22. Location of each step

23. Light dependent stage

25. Light dependent stage Electrons excited and emitted
Electrons accepted by electron acceptors
Electrons moved down ETCs
Losing energy (linked to ATP production)
Production of reduced NADP and ATP
Both needed in the next stage

26. Cyclic or non-cyclic?

27. Comparison Cyclic Non-Cyclic Photosystem I is final e- acceptor
Only ATP produced
NADP is final e- acceptor
ATP and reduced NADP produced

28. Box activity
Complete the order for light dependent photosynthesis.

29. Light independent Stage
CALVIN CYCLE
Occurs in the stroma of the chloroplasts
Involves a variety enzyme catalysed reactions.
Uses the products of the light dependent stage (ATP as an energy source and reduced NADP as a source of the reducing power to reduce CO2 and synthesise hexose sugar.

30. Check the typing on yours:

31. Light independent Stage
Enzyme reactions
RuBISCO
‘fixing’ of CO2
Needs ATP and reduced NADP to take place – from LDS.
ATP 

32. In Pairs on a whiteboard – 6 minutes to answer these questions

33. Ribulose bis phosphate
palisade
Calvin cycle
Ribulose bis phosphate
Absorb light
Absorption spectrum: % light absorbed by the pigments at
different wavelengths
Action spectrum: the rate of photosynthesis of a plant at

34. Box Activity Photosynthesis sort/order

35. Research Methods
How has photosynthesis been studied

36. Engleman

37. Jun 08
a) Fully explain the results of this experiment (3)

39. Calvin

40. Explain how the hydrogen is being formed during photosynthesis (1)
What would be the normal hydrogen acceptor in the chloroplast? (1)
What conclusions may be drawn from the results shown in the table? (2)