Biology 1202 Notes
Thursday January 17
Mastering biology course id=MBPOLLACK01639
Life first appeared on earth about 4 billion years ago
Origin of life is a hypothesis not a theory
Very little oxygen in early earths atmosphere Spontaneous generation of life- random formation of life
Millions of species on earth, up to 100 million the expirement of miller and urey showed what? test question a few centuries ago: people thought that new living things appeared all of the time(spontaneous generation of life) ex: mold growing on food in the mid 1800s Louis Pasteur refuted the theory of spontaneous generation of life he basically left something out but sealed it off and nothing grew on it, then he left it out without being sealed and stuff grew the cell theory- all existing cells come from pre-existing cells about 50 trillion cells make up the human body but all came from the single diploid cell formed from conception conditions on early earth: atmosphere- similar to Jupiter today, no free oxygen, frequent storms with lots of lightning, volcano eruptions, meteor impacts, UV light from the sun, no ozone layer earth before life arose: about 4.6 billion years old, known because of radiometric dating of meteorites and moon rocks life arose about 3.8 billion years ago, known because of chemical traces in the rocks, fossilized bacteria was found in rocks 3.5 billion years ago no spontaneous generation now but must have happened then how to assemble a living thing: accumulation of organic molecules catalyze reactions reproduce from stored genetic info separate the living thing from the outside environment
3 domains of life- bacteria, archaea, eukarya proteins are needed to synthesize more DNA
DNA is used to synthesize RNA which is used to make protein…DNA-RNA-Protein
Ribozymes: RNA molecule that can catalyze reactions, especially those involved in synthesis and processing of RNA itself Conclusion- earliest cells used RNA to store info Ribozymes used to
Mastering biology course id=MBPOLLACK01639
Life first appeared on earth about 4 billion years ago
Origin of life is a hypothesis not a theory
Very little oxygen in early earths atmosphere Spontaneous generation of life- random formation of life
Millions of species on earth, up to 100 million the expirement of miller and urey showed what? test question a few centuries ago: people thought that new living things appeared all of the time(spontaneous generation of life) ex: mold growing on food in the mid 1800s Louis Pasteur refuted the theory of spontaneous generation of life he basically left something out but sealed it off and nothing grew on it, then he left it out without being sealed and stuff grew the cell theory- all existing cells come from pre-existing cells about 50 trillion cells make up the human body but all came from the single diploid cell formed from conception conditions on early earth: atmosphere- similar to Jupiter today, no free oxygen, frequent storms with lots of lightning, volcano eruptions, meteor impacts, UV light from the sun, no ozone layer earth before life arose: about 4.6 billion years old, known because of radiometric dating of meteorites and moon rocks life arose about 3.8 billion years ago, known because of chemical traces in the rocks, fossilized bacteria was found in rocks 3.5 billion years ago no spontaneous generation now but must have happened then how to assemble a living thing: accumulation of organic molecules catalyze reactions reproduce from stored genetic info separate the living thing from the outside environment
3 domains of life- bacteria, archaea, eukarya proteins are needed to synthesize more DNA
DNA is used to synthesize RNA which is used to make protein…DNA-RNA-Protein
Ribozymes: RNA molecule that can catalyze reactions, especially those involved in synthesis and processing of RNA itself Conclusion- earliest cells used RNA to store info Ribozymes used to