1. Photosynthesis
Chapter 7

2. Producer Harvest sun energy Autotroph Photosynthesis
Organisms that make their own organic matter
Carbohydrates
Lipids
Proteins
Nucleic acid
Photosynthesis
chloroplast

3. Who Uses Photosynthesis

4. Who Uses Photosynthesis
Some protozoa

5. Who Uses Photosynthesis
Some Bacteria like cyanobacteria

6. Photosynthesis Harvest of light energy from sun and convert to glucose
Uses co2 & water
Produces glucose & oxygen
Occurs in the chloroplast
Uses pigments (Chlorophyll a & b)
Metabolic pathway (Reduction Oxidation)
Light phase
Dark phase (calvin cycle)

7. Photosynthesic Structures
Green parts of plants (or animals) contain chloroplasts
Concentrated in leaves
½ million/ Sq mm
Chlorophyll (a&b)
Green pigment
Stomata used to regulate gas availability

8. Stomata Regulate Gas exchange= co2, o2, water vapor
Reduce water evaporation
6Co2 + 6H2O
C6H12O6 +6O2

9. Chloroplast Membrane bound organelle Stroma- space
Granum of stacked thylakoids
Site of photosynthesis
Interconnected membrane sacs
Stroma
Granum

10. Light Light interacts with matter Electromagnetic energy (radiation)
Aka visible light
Contains energy
Light interacts with matter
Reflected
visible
Transmitted
Visible
Absorbed
Pigments
Energy form changes

11. Why are Plants are green?
Absorb red, orange, blue, green
Reflect or transmit green

12. Photosynthetic pigments
Chlorophyll a
Blue-green
Absorbs Violet-blue & red light
Chlorophyll b
Yellow-green
Accessory pigment
Absorbs Violet-blue & red-orange light
Carotinoids
Yellow-orange
Absorb violet & blue-green
Broaden absorption
Photoprotection
communication

13. Photosynthesis How Does It Do That???

14. Photosynthesis Light reactions Dark reactions Require light
Convert solar energy to chemical energy
Dark reactions
Synthesis
Produces sugar

15. Light stage Converts light energy into chemical energy
Chlorophyll absorbs light
Use light energy to split water
H is taken from H2O
Produce oxygen gas as waste
Energy harvesting stage
Cycles ADP to ATP
Cycles NADP+ to NADPH
Energy
Harvesting

16. Electron from water travels down the electron transport chain
Creates H+ gradient
Chemiosmosis

17. So Far we have ATP & NADPH
But doesn’t photosynthesis make sugar??
Where’s the Sugar?

18. Dark Reactions Aka calvin cycle Light independent
No direct investment of light required
Series of reactions that assemble glucose
Use co2 & energy sources (nadph, atp) from light reactions

19. Cellular Respiration vs Photosynthesis
H from sugar to o to make water
exergonic
Electron transport chain harvests E
Photosynthesis
H from h2o to co2= sugar
Endogonic
Uses light energy to drive
Electron transport chain harvests