BIOL 102 Lecture Notes - Lecture 9: Endoplasmic Reticulum, Stromatolite, Cellular Respiration
14 Feb 2017
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Past organisms were very different from those now alive. Fossil record shows macroevolutionary change over large time scales: exs: Conditions on early earth made the origin of life possible. However, evidence is not yet convincing that the early atmosphere was in fact reducing. Instead of forming in the atmosphere, the first organic compounds may have been synthesized near volcanoes or deep-sea vents. Miller-urey-type simulated atmosphere experiments demonstrate that organic molecules could have formed with various possible atmospheres. Rna monomers have been produced spontaneously from simple molecules. Small organic molecules polymerize when they are concentrated on hot sand, clay, or rock. Miller-urey-type simulated atmosphere experiments demonstrate that organic molecules including catalysts could have formed with various possible atmospheres. Replication and metabolism are key properties of life and may have appeared together in protocells. Protocells may have formed from fluid-filled vesicles with a membrane-like structure. In water, lipids and other organic molecules can spontaneously form vesicles with a lipid bilayer.
