Origins of life Flashcards
Non living replicating organics
Viruses and prions
Living replicating organics
Prokaryotes and eukaryotes
Louis Pasteur
Proved live comes from life with has broth experiment. He boiled water in 2 swan neck flasks with the neck bent in a sideways S shape that was open. That way, microbes would get stuck in the pit of the neck. He broke one flask and microbes grew in there, but nothing grew in the normal one. It was open to counterargue that “life force” could not enter the flask
5 steps of how life developed
- liquid water
- Abiotic synthesis of small organic molecules(shock synthesis)
- Building polymers from monomers:RNA is catalytic, as surfaces get crowded with them, polymers formed
- Packaging he polymers, separating internal/external environments
- Self replication and inheritence
Miller-Urey experiment
Life as known from early earth was replicated in a sealed system, and it was found that after running the system, 20+ amino acids were found
Micelle
ball of phospholipids with no layers, bring stuff into cells
Montmorillonite clay
Fine, microscopic crystals where vesicle numbers are found to be high
RNA replicase
make RNA from RNA template
How did DNA rise?
It was naturally selected over RNA because it is more chemically stable due to having less oxygen than RNA
Cyanobacteria
Can form larger structures, fossilize, are more complex than most bacteria. Consist of oldest fossils
What lead to the 2 big increases of oxygen in earth’s atmosphere? what were the effects
1st increase: presence of photosynthesis of prokaryotes
2nd increase: presence of plants
these increases likely lead to mass extinction of organisms surviving in oxygen poor environments
From who did mammals evolve from?
Fish, then reptiles, then mammals
What do we know and what dont we know about early life?
We know the “ingredients” but not the “recipe”
What factors were important to early life?
- cell membrane
2. Genetic material
What is RNA made up of
A sugar, phosphate and a base
