BIOL 1103 LECTURE NOTES Historical Figures in Science o Aristotle is very first person to write about spontaneous generation Believed in abiogenesis life from non life o Theophrastus Paracelsus was Swiss medical philosopher o Van Helmont was a physician and alchemist Experimented with how to produce draw mice with a dirty shirt in a vessel o Fransisco Redi was first scientist to really emphasize biogenesis as opposed to abiogenesis life comes from previous life To determine biogenesis experimented with decaying fish Put decaying fish in vessel uncovered and flies appeared life from life put decaying fish in vessel and covered with clay and no flies appeared Believers in abiogenesis believed that the clay was trapping the soul of the fly out and thereby not allowing it to reproduce Redi put sheath cloth over vessel with decaying fish to let the flies soul in still no flies appeared This experiment is considered to have debunked abiogenesis theory o Van Leeuwenhoek is the inventor of the microscope First person to find bacteria free living and parasitic microscopic protists sperm cells blood cells Leeuwenhoek contradictory to Redi s experiment thought that these microbes arised from spontaneous generation o 1860 French Academy of Science offered reward to anyone who could prove one way or another about spontaneous generation o T Schwann experimented to show biogenesis of microorganisms in 1837 o Louis Pasteur experimented with spontaneous generation Used a swan necked flask experiment diagram in book Won reward from French academy and officially disproved abiogenesis o Cell theory all life is made of cells and all cells come from previously existing Cell Theory cells o Atoms the smallest particle of any element o Subatomic particles protons neutrons electrons o Atoms has never been seen o Atomic number number of protons this number is always equal to the o Atomic mass mass of protons neutrons and electrons though electrons have number of electrons practically no mass o Electrons occur in pairs in stable atoms o Molecule combo of atoms such as water methane glucose Bonds o Bond connection of one atom to another Covalent strongest ionic and hydrogen bonds o Louis Dot model created to show covalent bonds by using dots instead of usual dashes o Valence electrons how many pairs of electrons are shared covalence Hydrogen has 1 valence Oxygen has 2 valences Nitrogen has 3 valences Carbon has 4 valences o Ionic bond results from gain or loss of an electron Ion atom that s gained or lost an electron and now has a charge o Covalent bonds share electron pairs H atom H atom Covalent bond shared electrons
View Full Document
Unlocking...