1. How is energy from the sunlight transferred into chemical energy?
Photosynthesis
How is energy from the sunlight transferred into chemical energy?

2. What is photosynthesis?
The process by which energy from sunlight is converted into the energy of glucose
It occurs on plant leaves
Cuticle-protection
Stoma-gas exchange

4. Important Parts of the Plant
Stroma
Thylakoids
Granum (Grana)

5. Pigments in plants
Chlorophyll: main energy absorbing molecule in chloroplasts
Carotenoids: plant pigments that are in plants
Yellow, orange, red
Cannot be seen until chlorophyll dies off

6. Main stages of photosynthesis
Light Dependent Reactions
Occurs within the thylakoids/grana
Light Independent Reactions
Occurs in the stroma

7. Light dependent reactions
Sometimes simply called “light reactions”
Energy from sun is absorbed and changed into chemical energy which is stored in ATP and NADPH
NADPH is specific to plants
Occurs in five steps

8. Step #1
Light strikes thylakoid and hits chlorophyll causing electrons to become excited

9. Step #2
Electrons jump from chlorophyll to chlorophyll through the thylakoid membrane (electron transport chain)
NADP+ picks up a high energy electron and H+ to become NADPH

10. Step #3 H20 is split by light (photolysis)
Electrons are given back to chlorophyll
O2 is released
Where does this occur?

12. Step #4
H+ builds up inside of the thylakoid

13. Step #5
H+ passes through transport protein (ATP Synthase) which adds P to ADP which forms________
Pointing outwards towards the stroma

14. Light dependent reactions
Reactants
Products
Sunlight
Water
Chlorophyll
Oxygen
ATP**
NADPH**

15. Reactants H2O CO2 Light Chloroplast C6H12O6 Glucose O2 Products
NADP+
ADP + P
Light
Dependent Reaction
Calvin Cycle
ATP
NADPH
Chloroplast
C6H12O6
Glucose O2
Products