1. 8-3 The Reactions of Photosynthesis
The difference is night and day!
Interactive: pgs

2. Inside a Chloroplast Thylakoids Stroma Saclike membranes
Arranged in stacks called grana
Organize the chlorophyll into clusters called photosystems
Stroma
Area outside the thylakoid membrane

3. Thylakoid compartment Stroma Thylakoid
Chloroplast
LEAF CROSS SECTION
MESOPHYLL CELL
LEAF
Mesophyll
CHLOROPLAST
Intermembrane space
Outer
membrane
Granum
Inner membrane
Grana
Stroma
Thylakoid compartment
Stroma
Thylakoid

4. Electron Carriers (The electron transport chain)
Sunlight gives energy to electrons in the chlorophyll of a plant
NADP+
A carrier molecule
Can carry 2 high energy electrons and 1 H+
NADPH
Results from adding 2 electrons
Traps the energy in chemical form
Can be used by chemical reactions in the cell

6. Light Dependent Reactions
In the thylakoid membrane of the chloroplasts
Use energy from light to make O
Converts ADP to ATP
Converts NADP+ to NADPH

7. 5 Steps (Light Dependent Reactions)
1. Photosystem II- absorbs light and breaks up water
2. Electron Transport Chain- moves high energy e- and transports H+ inside the thylakoid
3. Photosystem I uses the e- & H+ to turn NADP+ into NADPH
4. Hydrogen Ion movement makes the outside - and inside +.
5. ATP formation- H+ move outside the membrane and ATP synthase creates ATP.

8. Light Dependent Reactions
Thylakoid compartment (high H+)
Light
Light
Thylakoid membrane
Antenna molecules
Stroma (low H+)
ELECTRON TRANSPORT CHAIN
PHOTOSYSTEM II
PHOTOSYSTEM I
ATP SYNTHASE

9. The Calvin Cycle
Uses ATP and NADPH made during the light dependent reactions
Makes High Energy Sugars like Glucose
Does not require light
Occurs in the Stroma

10. 4 Steps 6 CO2 molecules + 6 C5 molecules = 12 C3
The resulting 12 C3 molecules are converted to higher energy molecules by using ATP and NADPH
2 of the C3 high energy molecules are used to make sugars, lipids, amino acids for metabolism and growth
The remaining 10 C3 molecules are recycled back into 6 C5 molecules to start the cycle again.

12. Factors that Affect the Rate of Photosynthesis
Amount of Water
Temperature
Photosynthetic enzymes function best at 0-35 degrees C
Light Intensity

13. Review: Photosynthesis uses light energy to make food molecules
Chloroplast
Light
Photosystem II Electron transport chains Photosystem I
CALVIN CYCLE
Stroma
Electrons
Cellular respiration
Cellulose
Starch
Other organic compounds
LIGHT REACTIONS
CALVIN CYCLE

14. Quiz Ch.8 What type of organism uses light energy to make its own food
Which compound is used to release energy to power the cell: ATP or ADP?
What is the name of the process that converts light energy into high energy carbohydrates?
Write the equation for the above process.
(you may use words or chemical formulas)
What is the main light absorbing pigment in plants?