MICROBIO 310 Lecture Notes - Lecture 16: Crenarchaeota, Mitochondrion, Proteobacteria
23 Mar 2016
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Document Summary
First evidence for microbial life is found in rocks 3. 86 billion years old. Early earth: anoxic and hot first biochemical compounds were abiotic (physical rather than biological) Subsurface origin hypothesis: life originated at hydrothermal vents on ocean floor steady and abundant supplies of energy (h2 and h2s) may have been available more stable conditions. Prebiotic chemistry of early earth set stage for self replication systems. Rna world theory: first self-replicating systems may have been rna based catalytic activity and self replication: rna can bind small molecules: atp and other nucleotides, rna has catalytic activity: may have catalyzed its own synthesis. Dna: more stable molecule became genetic repository. Three part system: dna, rna, and protein evolved and became universal among cells. Luca: last universal common ancestor population of early cells from which cellular life may have diverged into ancestors of modern day bacteria and archaea.
