1. Photosynthesis
Chapter 8

2. Trophs
Autotrophs
Heterotrophs

3. The Meaning of Life…

5. Photosynthesis 6CO2 + 6H2O C6H12O6 + 6O2
Photosynthesis uses the energy of sunlight to convert water and carbon dioxide into high-energy sugars and oxygen.
Green things are generally understood to be photosynthesizers

6. Chlorophyll Chlorophyll a Chlorophyll b
Pigments that absorb varying frequencies of light.
Poor absorbers of blue-green frequency

7. Chloroplasts
Thylakoids- contain photosystems which are the light-collecting units
Sunlight excites electrons in the chlorophyll which are then passed to electron carriers
(Sound familiar?)
NADP+ is charged with an electron to form NADPH

9. Light Dependent Reactions

12. Light Dependence
Two reactions are considered light-dependent in photosynthesis
Photosystem II absorbs light and produces energized electrons, H+ ions, and water.
Photosystem I receives tired electrons from II, are re-energized by sunlight, and used to make NADPH which passes to Calvin.

13. Mr. Calvin
ATP and NADPH from the light-dependent reactions are used by the Calvin Cycle to create sugars.

15. Factors Affecting Photosynthesis
Water availability
Sunlight intensity
Temperature (photosynthetic enzymes function best from 0-35 degrees C)
Light Wavelength

16. Back and Forth
light
6CO2 + 6H2O C6H12O6 + 6O2

17. O2 + sugar
CO2 + H2O