1. Producers and Consumers
Autotrophs (self-feeders):
Make their own organic matter from inorganic nutrients.
Heterotrophs (other-feeders):
Organisms that cannot make organic molecules from inorganic ones. 1

2. Energy Flow and Chemical Cycling in the Biosphere
Sunlight energy
enters ecosystem
CO2 (Carbon dioxide)
C6H12O6 (Glucose)
Photosynthesis + +
O2 (Oxygen)
H2O (water)
Cellular respiration
ATP
drives cellular work
Heat energy exits ecosystem 2

3. Photosynthesis Photosynthesis:
Is used by plants, some protists, and some bacteria
Transforms light energy into chemical energy
Uses carbon dioxide and water as starting materials
Light
energy
6 CO2
6 O2
6 H2O
C6H12O6
Photo-
synthesis
Carbon
dioxide
Water
Glucose
Oxygen gas 3

4. Photosynthetic Protists Photosynthetic Bacteria
Photosynthesis
Organisms that use photosynthesis are:
Photosynthetic autotrophs
The producers for most ecosystems
PHOTOSYNTHETIC AUTOTROPHS
Plants
(mostly on land)
Photosynthetic Protists
(aquatic)
Photosynthetic Bacteria
(aquatic) LM
Forest plants
Kelp, a large alga
Micrograph of cyanobacteria 4

5. found b/w lower and upper epidermis
Photosynthesis
found b/w lower and upper epidermis 5

6. Photosynthesis H2O CO2 Light Calvin Light cycle reactions O2 NADP+ ADP
Chloroplast
NADP+
ADP P
Calvin
cycle
Light
reactions
ATP
NADPH O2
Sugar
(C6H12O6) 6

7. *Photons are absorbed by pigment molecules
Photosynthesis
*photon
*Photons are absorbed by pigment molecules

8. Why Green? Light Reflected light Chloroplast Absorbed light
Transmitted
light 8

9. Light-harvesting complexes of the thylakoid membrane

10. Electron Flow

11. Organization of light reaction machinery

12. Chemiosmosis: A Comparison

13. Calvin cycle (Carbon Fixation)

14. Photosynthesis

15. Alternative Pathways C4 Pathway (example: sugarcane) CAM Pathway
ALTERNATIVE PHOTOSYNTHETIC PATHWAYS
C4 Pathway
(example: sugarcane)
CAM Pathway
(example: pineapple)
Cell
type 1
CO2
CO2
Night
Four-carbon
compound
Four-carbon
compound
CO2
CO2
Cell
type 2
Calvin
cycle
Calvin
cycle
Sugar
Sugar
Day
C4 plant
CAM plant 15