BIOL 1202 Chapter : Origin Of Life On Earth
Document Summary
Origin of life on earth: homoerectus 180 thousand years ago, first life: 4. 1 billion years ago. All cells come from pre-existing cells cell theory: hypothesis how did life begin, a few centuries ago, life was thought to generate appear over time. Spontaneous generation : existing species come from pre-existing species, spontaneous generation refuted, mid 1800"s louis pasteur killed preexisting microorganisms. Experiment of miller and urey least once: found some of the basic building blocks of amino acids, nucleotides, and sugars, did not find cells, found organic molecules appear after a few days. Rna molecule that can catalyze reactions especially those involved in synthesis and processing of rna itself: conclusions: earliest cells used rna to store info (rna first genetic material, ribozymes to catalyze reactions. Amino acid types: disulfide bonds (bridges) sytine and nathiamine, hydrophobic, hydrophilic. Cells that use rna: water plus elements and energy prebiotic soup (amino acids, nucleotides, lipids, sugars microspheres like protocels surrounding more complex organic molecules like.
