1. Photosynthesis

2. Ancient Earth – Before Photosynthesis

3. Today – Lush with Autotrophs

4. Thanks Plants!
Up to 85% of the Oxygen on Earth comes from photosynthetic autotrophs!
Plants filter the air and reduce atmospheric pollutants!
Shown: Vertical garden in Paris

5. Photosynthesis
Autotrophs internally create sugar (food) through absorbing water, carbon dioxide, and radiant energy from the sun
Photo = light
Synthesis = to make

6. Simple Sugar Uses Glucose – provides immediate energy for the plant
Starch – polysaccharide used for energy storage
Cellulose – polysaccharide used to strengthen cell wall

8. Photosynthetic Organisms

9. Pigment in green plants
Chlorophyll – pigment that reflects green light but absorbs blue and red light

10. Other pigments

11. Plant Cell

12. The chloroplast Sites of photosynthesis Double membrane
Pigment: chlorophyll (located in the thylakoid)
Light dependent reactions occur in the thylakoid
Light independent reactions occur in the stroma

13. Chloroplasts

14. Microscope View

17. Photosynthesis: an overview
The light-dependent reactions convert light energy into chemical energy (ATP).
The molecules of ATP produced in the light-dependent reactions are then used to fuel the light-independent reactions that produce simple sugars.
6CO2 + 6H2O → C6H12O6 + 6O2

18. What is ATP???
ATP= ENERGY
Adenosine Triphosphate or ATP is an energy molecule that provides direct energy to your cells
ATP is composed of an adenosine molecule with 3 phosphate groups attached

21. When the bond breaks, energy is released

22. What is ADP???
When one phosphate group breaks away, ATP becomes Adenosine Diphosphate (ADP)
ADP has only two phosphate groups and holds less energy than ATP
ATP ADP ATP

23. How do plants receive CO2?

24. Factors that affect the rate of photosynthesis:
Limiting factors

25. Light Dependent Reactions
Located in the thylakoid membrane
Pigment molecules are struck by light and give off an electron
Electron transport produces ATP
e- is replaced by splitting water (releases O2)

26. Light Independent Reactions
Also called the Calvin Cycle
Occurs in the stroma of the chloroplast
6 molecules of CO2 are converted into glucose

27. How Autotrophs Use Intermediates and Products of Photosynthesis
What do they do with the sugar??
Glucose is used as cellular fuel and as building blocks in synthesis of carbohydrates
Sucrose is transported from leaves to all parts of the plant
Starch is the main storage form of carbohydrate in plants
Cellulose is used to make plant cell walls

28. A review of photosynthesis