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Earth_2 - EvidenceofLife Cyanobacteria Stromatolites...

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Evidence of Life Cyano-bacteria Stromatolites
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What is Life? 1. Eat 2. Grow 5. Reproduce 3. Eliminate waste 4. Metabolize 6. Die 7. DNA/RNA
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Amino Acids Basic building blocks of proteins Found in pre-Cambrian rocks and meteorites Miller-Urey Experiment Methane    Ammonia   Hydrogen    Water
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Polypeptides Protein-like chains Sydney Fox – heating amino acids in  phosphoric acid yields polypeptides Cooling yields “proteinoid microspheres” Spheres  grow   and bud  ( reproduce ) Sphere walls  are osmotically  active
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Some  microspheres  aggregate into            larger bodies
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Liposomes Phospho-lipid (fatty acids) spheres  Used today for medicine delivery Wall structure resembles a cell Selectively osmotic Jack Szostak – HHMI- RNA inside  liposome makes it competitive      (can  eat  other spheres)
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If liposome encapsulates catalytic activity – then  have simple  metabolism
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Example – PTS protein associated thermosythesis
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Where did proteins come from? structural template. Clay minerals may have provided template Jack Szostak observed spontaneous formation  of a catalyst in random nucleotides that can  join the nucleotides and derives its energy  from triphosphate groups – very similar to  RNA  –precursor to  DNA
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What about real life? Eukaryotes:  large cells >40um, organelles,  nucleus, chromosomes Prokaryotes: Small cells,  no organelles,  no nucleus,  no chrosomes  (scattered DNA) Viruses Prions
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Earth_2 - EvidenceofLife Cyanobacteria Stromatolites...

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