1. Plants are awesome
They really are!

2. GCSE Knowledge Plant Cells – draw one now
Plant growth – what effects it?
Plant nutrition – what this mean?
Plant distribution – what effects it?
A2 – photosynthesis and hormones

3. Right let us begin Why do plants need energy?
To do photosynthesis, DNA replication, growth, active transport
What processes do they use to create a store of energy?
Photosynthesis, respiration (anaerobic and aerobic)
Two equations write them now!

4. ATP What is it? How is it made? How is it used?
What are it’s properties?
Small amount of malleable usable energy, soluble, easily broken down, transfers energy by phosphate groups, can’t leave the cell so readily available

5. Plants and energy
Both Respiration and Photosynthesis occur at the same time, dependent on light intensity
The light intensity at which both happen at the same time this is the Compensation Point for light intensity
You can show the compensation point because the net production/use of oxygen will be zero

6. Questions Name three processes that require energy in a plant
Outline the relationship between the raw materials and products of photosynthesis and respiration
What is the function of ATP?
Describe the structure of ADP and ATP
What is ATP broken down into by ATPase and what is the process called

7. Next Steps Draw a chloroplast and describe the structures
Lets see what you can remember

8. Chloroplast Structure
Chloroplasts are little self contained organelles that act like little autonomous cells in the plant cell
They have their own DNA
They have their own ribosomes
They pair up with Mitochondria (they be needing their glucose)

9. More structure
Double membrane (so and inner and outer) called the chloroplast envelope
They contain loads of membrane bound sacs called THYLAKOIDS these are stacked up into Grana (sg granum)
Grana are inked together with lamella which are bits of thylakoid membranes (pl lamellae)
They contain pigments attached the proteins in the membranes – chlorophyll a and b, carotene
These harness light the protein and pigment is called a photosystem
There is also a cytoplasm like substance called stroma – this stores Glucose in starch grains, enzymes, sugars and organic acids

10. What it all looks like!

11. Reactions
Simple little thingies these are they are the sites for two reactions
Light dependent – using water
Light independent – using carbon dioxide
Both are there to make one molecule - Glucose

12. Now how it all works! It is all really to do with chemistry!
Remember Redox
Oxidation is Loss of electrons or the gain of oxygen
Reduction is Gain of electrons or the gained hydrogen or lost oxygen
It always happens in pairs

13. Important points
There are two photosystems in the light dependent reaction PSI (700nm) and PSII (680nm)
The photosystems exist to excite electrons
The process involves the very important coenzyme NADP (reduced NADPH) this molecule can oxidise (remove Hydrogen) or reduce (add hydrogen)

14. Simple idea of the light dependent reaction
I will warn you now this is complex!
Right
Simply put the light dependent reaction is there to
Make ATP from ADP
Make NADPH from NADP
Both of the above transfer energy to the light independent reaction
The electrons for this process come from Water and produce Oxygen and protons (hydrogen ions) through photolysis (what do you think this means?)

15. Non Cyclic Photophosphorylation
Great word!
First the basics remember we had how many photosystems?
2 – PSII (680nm) and PSI (700nm)
They are both linked by electron carriers (proteins that transfer electrons)
Happy so far?

16. 1. Light energy excites the electrons in chlorophyll
Light energy is absorbed by PSI
This in turn excites electrons on Chlorophyll
This creates a high energy electron
These electrons move to PSI

17. 2. Photolysis of water produces protons, electrons and oxygen
As the excited electrons leave PSII they must be replaced
Light splits water into H+ ions (or protons) electrons and oxygen at PSII
Equation – H2O → 2H+ + ½ O2

18. 3. Energy from the excited electrons makes ATP
The electrons lose energy as they pass along the transport chain
This energy is used to pump more H+ ions into the thylakoid via protein proton pumps
Therefore more H+ in the thylakoid than without
Hydrogen then moves down the gradient back out through ATP synthase and the energy from this makes ATP

19. 4. Energy from the excited electrons generates NADPH
Light is absorbed by PSI
This excites the electrons even higher
These higher energy electrons can reduce NADP to NADPH (reduced NADP)

20. Starter
On a fresh sheet of A3 – try to diagram the light dependent reaction
This is a revision task to see what you can remember
Enjoy!!

21. Cyclic Photophosphorylation
No electron chain
Only one PS, PSI
No NADPH made only ATP
And not a lot of ATP

22. Light Independent – using the ATP and NADPH
The Calvin Cycle!!!!
This is awesome and is how plants make glucose, even in the dark people!
It uses the energy stored from the light dependent stage
Cool yes??

23. The steps and stages
All this happens in the stroma (that is where the ATP and reduced NADP (NADPH) lives remember
It makes a molecule called triose phosphate from CO2
And it makes ribulose phosphate (5 carbons)
This is such fun already

24. Step 1 – formation of glycerate 3 phosphate
CO2 enters the leaf through the stomata
In the stroma it is combined with Ribulose Bisphosphate (5 carbon) RuBP
This makes an unstable 6 carbon molecule that breaks into two Glycerate 3 Phosphate molecules GP
This is catalysed by Ribulose bisphosphate Carboxylase (RuBisCO)

25. Step 2 – Formation of Triose Phosphate
GP is reduced to a different 3 carbon compound called
Triose Phosphate TP the energy comes from ATP
The Hydrogens required come from reduced NADP (NADPH)
The TP is then used in different reactions to make useful sugars

26. Stage 3 – Regeneration of RuBP
Five out of the six molecules of TP from each reaction aren’t used to make glucose or other useful compounds
They are used to generate more GP and TP
More ATP is used to combine 2 GP molecules into one RuBP and one single carbon

27. How many cycles
The Calvin cycle needs to turn 6 times to produce one hexose sugar
Each three turns make six 3 carbon GP molecules
Five are used to regenerate RuBP
So we need six turns to make the two needed for one hexose sugar
So six turns – 6 CO2 and 18 ATP and 12 NADPH
How many light dependent reactions do you need????

28. Here it is

29. Use of the 3c molecules
Carbohydrates – hexose (6c) sugars are made from two TP molecules and larger ones are made from joining hexose sugars together
Fats – Made using glycerol which is made from TP, and fatty acids which are made from GP
Amino Acids – some are made from GP

30. Questions to Start Peoples