BSC 116 Lecture Notes - Lecture 1: Stromatolite, Multicellular Organism, Tetrapod
17 Jan 2017
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Document Summary
Life on earth is at least 3. 5 billion years old: chemical/physical processes on early earth may have produced simple cells in sequential stages. C, n, and small amounts of o in the atmosphere. Early atmosphere likely contained water vapor and chemicals released by volcanic eruptions. Nitrogen, nitrogen oxides, carbon dioxide, methane, ammonia, hydrogen, hydrogen sulfide. Atmosphere of early earth was probably a reducing environment. Continuous growth until eventually forming a protein, carbohydrate, or fatty acid. Origin of self-replicating molecules: atmosphere was much different than that of which we have today. Miller-urey experiment- hypothesied that the atmosphere of early earth was probably a reducing environment: amino acids, nitrogenous bases, and other simple organic molecules, evidence for this hpothetical atmosphere is not entirely convincing. Another possibility- first organic compounds were synthesized near submerged volcanoes and deep-sea vents: one possible scenario: Reducing environment gave rise to organic molecules (amino acids, nucleic acids, lipids, etc. Catalytic rna molecules (ribozymes) capable of self-replication former.
