01:119:115 Lecture Notes - Lecture 4: Harold Urey, Stanley Miller, Ammonia

• School: Rutgers University
• Department: Biological Science
• Course: 01:119:115
• Professor: Stern Cardinale

Document Summary

Chemical evolution: fossil evidence of microorganism is 3. 5 billion years ago: hypothesis: life developed from non-living matter, 4 requirements: conditions of early earth. Little or no free o: oxygen oxidizes breaks bonds, o2 not conducive to building, atmosphere high in reduction conducive to building. Source of energy: build biological molecules form inorganic chemicals: violent thunderstorms, volcanic activity, meteorite bombardment, intense radiation (no ozone). Presence of chemical building blocks: water, dissolved inorganic minerals (ions), atmosphere contained co2, h2o vapor, co, h2 and n2; maybe nh3, h2s, Time: for molecules to accumulate and react: estimated earth is 4. 6 billion year old, evidence that life arose on earth: 3. 5 billion year old. 4 steps hypothesis of single cell formation: abiotic synthesis: small organic monomers formed spontaneously; two models, prebiotic soup hypothesis = sea of organic soup; oparin-haldane hypothesis. Formed amino acids + other organic molecules: recent developments 2008: atmosphere may have been neutral, not reducing.