BIO_SC 1500 Lecture Notes - Lecture 7: Gram Staining, Nrg Energy, Gram-Negative Bacteria
20 Mar 2017
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*nrg energy: ph ii evolved from ph i ~3. 2 billion years ago in cyanobacteria. Lecture 2: measures oxygen and carbon isotopes ratio in co2 and methane in samples on mars in order to distinguish between their geochemical or biological origin. Appearance of aerobic life: from ~ 3. 2 billion years ago when ph ii evolved until ~2. 5 billion years ago, Billion years ago: ~2. 5 billion years ago o2 liberated by ph ii began to oxidize fe+2 to fe+3 (ferrie) which is insoluble in water and forms fe2o3 (rust, overtime oceans then atmosphere became enriched with free o2. 1b2 one problem in establishing relationships is horizontal gene transfer in prokaryotes. Cells have nucleus and other organelles: eukaryotes first appeared 1. 8 2. 8 billion years ago. Features of eukaryotic cell: has a nucleus containing most of its dna in linear form in chromosomes, has organelles structures that compartmentalize eukaryotic cells and allow complex metabolism, most have cell walls (not animal cells)
