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Photosynthesis - Coggle Diagram
Photosynthesis
Pigments
Started as "sunscreen" to protect plant
Why?
Early atmosphere had little oxygen, so no protective ozone layer
When?
Cyanobacteria developed Scytonemin in sheath to protect it from UV radiation
What are they?
Particles that absorb wavelength of light energy and reflect others
What do they do
Absorb light energy
When plants absorb light energy
electrons become excited and bump into next orbital
Causes electron to
pass to electron acceptor
Fall back down to original orbital
Origins
Stromatolites
3.5 BYA
Cyanobacteria
3.5 BYA
Oldest known fossilized organism
Layers of photosynthetic bacteria/ cyanobacteria
Secretes mucilage
bands of sediment & dead bacteria similar to coral reef
Evidence
Early earth no oxygen
Photosynthesis
Evolved under high CO2 conditions and produced Oxygen
Photosystems
Photophosphorylation