MICRJ-210 1st Edition Exam # 1 Study Guide Lectures: 1 - 6Lecture 1 (January 12)The Early Years of Microbiology- Antoni von Leeuwenhoek o Made simple microscopes and examined water dropletso Called them “animalcules”- Carolus Linnaeso Developed the taxonomic system in order to name these microorganismso Categorized into six different groups Fungi- Eukaryotic (contain nucleus)- Obtain food from other organism (like an animal)- Contain a cell wall (like a plant)- Include both molds and yeastso Mold: multicellularo Yeast: unicellular Protozoa- Eukaryotic - Unicellular- Contain pseudopods, cilia, and flagella Algae- Photosynthetic eukaryotes Bacteria- Prokaryotes- Asexual- Cell wall is made of peptidoglycan- Live in mild environments- Can be both beneficial and harmful Archaea- Prokaryotes- Live in extreme environments- Not known to ever cause disease Small multicellular animals (such as parasitic worms)- Varies with speciesThe Golden Age of Microbiology- Scientists searched for answers to four questionso Is spontaneous generation of microbial life possible? This was first suggested by Aristotle and has been disproveno What causes fermentation? During these times, drinking water was highly notorious for causing infections, so fermentation was used to eliminate pathogenso What causes disease?o How can we prevent infection and disease?- Francesco Redi’s Experimentso Three jars of meat: uncovered meat grew larvae, sealed jar did not grow larvae, and gauze covered jar with meat did not grow larvaeo As a result, people began doubting spontaneous generation The larvae did not spontaneously generate in the sealed and gauze covered jars- Louis Pasteuro Created swan necked flask that allowed air to freely flow to a boiled bacteria-freeinfusion He prevented particulate matter from reaching the infusion After months, the infusion remained sterile Disproved the theory of spontaneous generation for goodo His experiments helped lead to the development of the scientific method Observe Ask a question Generate a hypothesis Test through experiments Compare results with hypothesis- Disprove or prove hypothesiso Pasteur and Fermentation Spoiled wine threatened livelihood of vintners Many believed that air caused fermentation (which erroneously supported spontaneous generation)- Pasteur however, proved that fermentation was caused by yeast Yeast ferments grape juice into alcohol- First the juice is heated to kill all pathogens, then inoculated with yeast and sealed. The Yeast reproduce and alcohol is producedThe Golden Age of Microbiology- What causes disease?o Ignaz Semmelweiss noticed that “cadaverous material” from doctor’s hands working in the cadaver lab was infecting mothers in labor with childbed fever He advocated for the washing of hands in bleach and the mortality rate dropped by 90%o Louis Pasteur developed a germ theory of diseaseo Robert Koch studied causative agents of a disease Anthrax was infecting cattle and killing livestock-he was able to isolate and examine colonies of microorganisms Koch’s Postulates- Suspected causative agent must be found in every case of the disease and be absent from healthy hosts- Agent must be isolated and grown outside the host- When agent in introduced into a healthy, susceptible host, the host must get the disease- Same agent must be found in the diseased experimental host- Extra Reading assigned by professoro Semmelweis advocated for hand washingo Lister developed an antiseptic techniqueo Nightingale and Nursingo Snow and Epidemiology Studied cholera epidemic and traced source to water supply Highlighted critical need for proper water supply and sewage treatment- Infections control- Epidemiology (the study of the occurrence, distribution, and spread of disease)o Jenner’s vaccine Infected boy with cowpoxsurvived and then infected him with smallpox survived Began the field of immunology Developed vaccines against smallpox, fowl cholera, anthrax, and rabiesMicroscopy- Light Microscopes o Light wavelength varies and can’t resolve small enough to see small microbes butare shown in color- Electron Transfer Microscopeso Electrons have a very short wavelength and you can see more detail but are NOT in coloro Transmission: Electrons penetrate sample directlyo Scanning: Electrons bounce obliquely off of sample to a receptorLecture 2 (January 14)Eukaryotes and Prokaryotes- Eukaryotes: diploid cells (contain 2 copies of DNA) and have a true nucleus- Prokaryotes: haploid cells (contain 1 copy of DNA)o Composed of bacteria primarily as well as archaea - Pathogens can come from bacteria and eukaryotes but never archaea- Phylogenic Treeo Archaea Similar to bacteria but live in very harsh environments (hot springs, soils, and salt lakes, etc.)o Bacteria (can be both beneficial and harmful to humans)o Eukaryotes Have a true nucleus with a nuclear membrane Can also be pathogenic (i.e. protozoa or parasitic worms)- Other facts to know:o Bacteria do not undergo meiosis because they reproduce asexuallyo Membranous organelles are absent in ALL prokaryoteso The cell membrane of bacteria “acts” as the membrane of mitochondria allowingATP to be produced Structure Differences between Eukaryotes and Prokaryotes- Structure of an animal cello True nucleus and membranous organelles Millions of base pairs tightly coiled around histoneso No cell wall- Structure of Prokaryotic cellso Single chromosome is arranged as a circle with both end bound together Cannot sexually reproduceo Pili (fimbriae) Appendages that attach to surfaces that act as anchoring devices Do NOT cause locomotiono Cell wall composed of peptidoglycan Because they do not have a cytoskeleton, bacteria derive their shape and form from the cell wallo There are no membrane-bound organelles so everything floats in the cytoplasm freelyLocomotion- Cilia: composed of microtubules and are smaller than flagella); short hair-like structures used to move particles across cell surfaceo ONLY found in eukaryotes Example: cilia on parameciumo Motion in is one plane (beating)- Flagella: long whip-like structure used for movemento Both in prokaryotes and eukaryoteso Motion in prokaryotes is rotation (spins around in axis: like a propeller)o Motion in eukaryotes is undulation (moves back and forth in one plane: like a
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