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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. Energy Flow and Chemical Cycling in the Biosphere. Sunlight energy enters ecosystem.
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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.
Energy Flow and Chemical Cycling in the Biosphere Sunlight energy enters ecosystem CO2 (Carbon dioxide) C6H12O6 (Glucose) Photosynthesis + + O2 (Oxygen) H2O (water) Cellular respiration drives cellular work ATP Heat energy exits ecosystem
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 C6H12O6 6 H2O Photo- synthesis Carbon dioxide Water Oxygen gas Glucose
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
Photosynthesis found b/w lower and upper epidermis
Photosynthesis CO2 H2O Light Chloroplast NADP+ ADP P Calvin cycle Light reactions ATP NADPH O2 Sugar (C6H12O6)
Photosynthesis *photon *Photons are absorbed by pigment molecules
Why Green? Light Reflected light Chloroplast Absorbed light Transmitted light
Alternative Pathways ALTERNATIVE PHOTOSYNTHETIC PATHWAYS CAMPathway (example: pineapple) C4 Pathway (example: sugarcane) Cell type 1 CO2 CO2 Night Four-carbon compound Four-carbon compound CO2 CO2 Cell type 2 Calvin cycle Calvin cycle Day Sugar Sugar CAM plant C4 plant