Bio 115 Cells & Evolution of Life
Energy Conservation
Autotrophy: A Way of Life
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Bio 115 Cells & Evolution of Life
What is an autotroph?
Photo by Hans Paerl/ASM
MicrobeLibrary
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Photo by Linda Fisher/ASM MicrobeLibrary
Bio 115 Cells & Evolution of Life
Photoautotrophs
Green plants & algae
CO2 + 2H2O light
→ (CH2O) + H2O + O2
Purple sulfur bacteria
light
CO2 + 2H2S → (CH2O) + H2O + 2S
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Chemoautotrophs
Bio 115 Cells & Evolution of Life
Red tube worms
Sea floor vent
Crabs and mussels in a
chemosynthetic ecosystem
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Bio 115 Cells & Evolution of Life
Photoautotroph verses Chemoautotroph
Nutritional
Category
Energy
Source
Carbon
Source
Photoautotroph
sunlight
carbon
dioxide
inorganic
molecules
carbon
dioxide
(plants, algae,
some prokaryotes)
Chemoautotroph
(some
prokaryotes)
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