Transcript Evolution of First Life

Evolution of First Life
Archaebacteria
• Thrives in harsh conditions
– Chemosynthesis instead of photosynthesis
• Sea vents and hot springs
• Snottites
Cyanobacteria and Stromatolites
• Sun can get through to the surface of the
Earth—but there is no ozone layer, no
protection.
• First photosynthetic bacteria
– Prokaryotes
– Simple organisms
• Earth is also cooling
Oxygenation of the Oceans and Air
• Cyanobacteria and stromatolites helped
oxygenate the oceans and the air
• Oxygenated the oceans first
– Went from olive green to blue
– Rusting of the oceans, turned red
• Next, atmosphere was oxygenated
– Rusting of the land, land turned red
• As the atmosphere was oxygenating the ozone
was also forming
Prokaryotes and Eukaryotes
Prokaryotes
• Primitive
• Bacteria
• Simple
• Small
Eukaryotes
• Advanced
• Plants and animals
• Complex
• Larger
Endosymbiosis
Eukaryotes
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Nucleus
DNA
Cytoplasm
Mitochondria
Ribosomes
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RER
Vacuole
Lysosome
Cell wall
Cell membrane
Chloroplasts and Mitochondria
• Mitochondria in animals and Plants
• Chloroplasts in plants only!
Both have a double membrane—remnants from
their Endocytosis beginning.
Both have their own DNA—which is similar to
the DNA in heterotrophic bacteria and
cyanobacteria.
Mitochondria
• C6H12O6 + O2 + H2O = CO2 + H2O
• Needs oxygen for cellular respiration so that
they can break the larger molecule of sugar
and get more energy
• Without oxygen, the cell will
Only be able to ferment which
Doesn’t provide enough energy.
Chloroplasts
• CO2 + H2O  C6H12O6 + O2
• Uses the carbon dioxide that we breath out to
make sugar for energy. Produces the oxygen
needed for eukaryotes to survive.