1. Photosynthesis
Why plants don’t “eat”

2. What is Photosynthesis?
Photo: Light
Synthesis: Putting Together
Photosynthesis: putting together with light!

3. Why are plants green? Chlorophyll absorb light All but green
Green is reflected back!

5. What are the two stages?
1st: Light-Dependent Reactions
2nd: Light-Independent Reactions

6. Where do Light-Dependent Reactions Occur?
In the thylakoid stacks of the chloroplast

7. What happens during the light-dependent reactions?
Sunlight powers the production of ATP
Water is broken down into oxygen
What is a waste product here?

8. What are the steps of Light-Dependent Reactions?
Photosystem II
Photosystem I
ATP Synthase

9. What happens during Photosystem II?
Chlorophyll absorbs sunlight
Sunlight powers electrons to leave H from H20 and move through membrane
H+ moves through membrane
If H leaves water, what is left?

10. What happens during Photosystem I?
Chlorophyll still absorbs sunlight
Electrons (e-) added to NADP+ to make NADPH
NADPH moves to the ATP Synthase
NADP+
ATP Synthase
Photosystem I
NADPH

11. What happens during ATP Synthase?
H+ ions move back through membrane
Power ATP Synthase to make ADP from ATP
Where have we seen this before?

13. Where do Light-Independent Reactions Occur?
In the stroma of the chloroplast

14. What happens during Light-Independent Reactions?
ATP made previously powers making of Glucose
CO2 is used to make C6H12O6 (Glucose)

15. How many steps are there in Light-Independent Reactions?
ONE!
The Calvin Cycle

16. What happens during the Calvin Cycle?
1. A 5-Carbon molecule attaches to a C from CO2 to become a 6-Carbon molecule

17. 2. Energy (ATP) breaks the 6-carbon into 2 3-carbon molecules

18. 3. 1 of the 3-carbon molecules leaves the cycle, the other continues on.

19. 4. Remaining 3-carbon has energy (ATP) added to become the 5-carbon molecule we started out with!

20. So how does that make a Glucose?
Glucose has 6 carbons…
The 3-carbon molecule that left, after 2 cycles, comes together to make Glucose!
3C+3C=6C