ISCI 1A24 Lecture Notes - Lecture 13: Louis Pasteur, Euglena, Spontaneous Generation
29 Sep 2016
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Euglena flagellated protists; can be animal (heterotrophic) or plant (autotrophic phagocytosis); make own food during limiting factors or in the presence of light, will phagocytize when other organisms are present; asexual reproduction; eukaryotes. Cell theory importance to modern biology. Hooke: first microscope looked at plant cells (mainly cork), first observed. Hoek: observed organisms in pond water, plaque on teeth; called them. Animalcules actually bacteria. cell highly organized compartment bound by a plasma membrane containing concentrated chemicals in an aqueous solution; ostrich eggs and 200nm bacteria both single cells. Spontaneous generation hypothesis cells arise spontaneously from nonliving materials. Cells-from-cells hypothesis cells only produced when pre-existing cells grow and divide. Louis pasteur invented pasteurization , which killed harmful cells: Placed nutrient broth in flask; boiled to sterilize and kill living cells in broth; one closed, one open to air; pre-existing cells enter flask from air, do not enter if closed.
