1. Photosynthesis

2. Photosynthesis The process plants use to trap the sun’s energy
Energy stored as glucose (C6H12O6)

3. Occurs in which organelle?
CHLOROPLAST!!
Three major parts
Intermembrane space
Thylakoid
Stroma

4. Intermembrane Space
-Space that separates the two layers of chloroplast membrane

5. Thylakoid CHLOROPHYLL!! Flattened membrane sacs inside chloroplast
Pigments contained here trap light
CHLOROPHYLL!!

6. Stroma
Fluid filled space that surrounds stacks of thylakoids (aka Grana)
Reactions that convert carbon dioxide to sugar occur here

7. Light Dependent Reactions
1st phase of Photosynthesis
Requires Light
Light absorbed by chlorophyll
Energy passed to electrons
Electrons passed on to the……………

8. Electron Transport Chain
Energized electrons are passed along from protein to protein embedded in the thylakoid membrane
Each time losing a little energy
Create ATP from ADP+P
Energy used to split H2O and form Oxygen
Create NADPH for use in light independent reactions

10. Why split H2O to make Oxygen?
Used to free electrons to return to chlorophyll……. So??
so the ETC won’t run out! And……
Photosynthesis can continue!

11. Light Independent Reactions
Melvin Calvin
Do not require Light
Fueled by ATP made in ETC
Known as the Calvin Cycle
Occur in Stroma

12. Calvin Cycle Takes Carbon from CO2 Forms carbohydrates
Uses ATP and NADPH
Takes 6 turns to create one molecule of glucose

14. Photosynthesis Equation
6CO2 + 6H2O=C6H12O6 + 6O2

15. Photosynthesis As a Process
Light energy absorbed; CO2 absorbed; O2 released from water; sugar produced
Plants split the water to release Hydrogen to make NADPH

16. Photosynthesis cont.
Plants absorb light to energize electrons in the thylakoid membrane
Sugars provide a more useful storage form for the energy in the electrons released from water

17. Energy Overview
Light reactions take energy in as light and store it as ATP and NADPH
Dark reactions take the energy stored in ATP and NADPH to make sugar molecules

18. Three Types of Plants C3 plants: Most plants are C3
These include rice, wheat, beans
C4 plants: have an adaptation to grow when stomata are closed
Plants In hot regions (sugarcane, crabgrass)
CAM plants: desert dwelling plants that open stomata at night
Cacti