1. 1. Light reaction Recap 2. Calvin Cycle (dark reaction)
Photosynthesis
1. Light reaction Recap
2. Calvin Cycle (dark reaction)

2. Talk to a Neighbor…
Using the following diagram, walk your partner through the 5 steps of the light-dependent reactions

3. Summary of Part 1:
Video clip
Using light energy ADP NADP+ H2O changed into ATP NADPH H+ & O2

4. (Light-Independent Reactions)
O2 gas is released as a by-product through the stomata (pores) on the leaf
The energy of ATP and NADPH are now used to power Part 2 of photosynthesis:
The Calvin Cycle
(Light-Independent Reactions)

6. Part 2: Calvin Cycle aka Light-Independent rxn or Dark rxn
Does NOT need light because energy from sun already captured in NADPH & ATP
Occurs in stroma

7. Calvin Cycle uses ATP & NADPH to produce high-energy sugars

8. Energy taken out of NADPH & ATP & combined w/CO2 & H+ forming C6H12O6

9. NADP & ADP recycled back to light reaction
Glucose can be converted by cells into lipids, proteins, nucleic acids, etc.

10. Calvin Cycle Video

11. Factors that affect the rate of photosynthesis?
Amount of water & CO2 (reactants)
Temperature - too high or low denatures enzymes
Intensity of light

12. Putting it Together…

13. Review light rxn

14. Reactants Diagram H2O CO2 Light Chloroplast C6H12O6 Glucose O2
Word Bank
H2O
Glucose
Light -Dependent
Chloroplast
Thylakoids
Grana
Calvin Cycle
Light O2
Stroma
Reactants
Products
H2O
CO2
Light
NADP+
ADP + P
Light
Dependent Reaction
Calvin Cycle
ATP
NADPH
Chloroplast
C6H12O6
Glucose O2
Products

15. Summary:
Light Dependent Reaction—H2O is broken down and light energy is stored temporarily in energy carriers, ATP and NADPH
Calvin Cycle—energy is transferred from ATP and NADPH to the organic compound glucose

16. Reactants Products

17. Questions??

18. What are the reactants for photosynthesis?
What are the products?

19. Where in the chloroplast do light-independent reactions occur?
Stroma

20. Where do the ATP and NADPH used in the Calvin Cycle come from?
Light Reactions

21. What are the 3 factors that affect the rate of photosynthesis?

22. Where does gas exchange occur on the leaf?

23. What happens to the O2 produced by the light reactions?

24. Cornell Summary