Medical Microbiology Exam 1 Questions and Answers correct

Medical Microbiology Exam 1 Questions and Answers correct Microbiology The study of microbes (microorganisms) - organisms so small that a microscope is required to see them What are the Microbes? Bacteria (bacterium)- Bacteriology Algae (alga)- Phycology Fungi (fungus)- Mycology Protozoa (protozoan)- Protozoology Viruses (virus)- Virology Why study Microbiology? 1. Microbes are important to human health and disease. 2. Microbes can increase our understanding of biology 3. Microbes are very useful in biological research Microbes are... - simple - grow rapidly - have unique and easy ways to transfer genetic information What's unique about algae? Multicellular, defined cell nucleus and other internal structures, Chlorophyll What's different about helminths? Macroscopic worms Have microscopic stages in their life cycles. What is an infectious disease? a disease caused by an infectious agent (bacteria, virus, fungus, protozoan, helminth) What is a noninfectious disease? a disease caused by any factor other than an infectious agent (i.e. cancer, Cystic fibrosis, heart disease, etc.) What percentage of microbes are pathogenic? less than 1% How are microbes useful? - In our food - Cleaning up our waste - Killing pests - Making medicines - In the making of such things as leather (Aspergillus niger), soy sauce, cheese and paper. - they generate oxygen, - are part of the carbon and nitrogen cycles, - can survive the harshest conditions. Where can you find microbes in our bodies? our mouths, GI tract, vaginal flora and on our skin Without microbes... our bodies would not process the food we eat Scope What's included in the discipline of Microbiology History Some key ideas, events, & people and their significance to the development of Microbiology Receptor mutation CCR5-delta 32 protein (on white blood cells involved in receptor for chemokines) Credit for the first microscope is given to ___________ in 1595. Zacharias Janssen Robert Hooke - Micrographia 1665 - Described a slice of cork as "cella" (cells) - Formed the beginnings of Cell Theory Anton Van Leeuwenhoek - Usually credited with the invention of the microscope. - Creates Leeuwenhoek's Lens System. - "animalcules" in pond water 1674 - living bacteria from tooth scrapings 1683 Carlous Linnaeus Developed a taxonomic system for grouping similar organisms together. Leeuwenhoek's organisms grouped into 6 categories. - Bacteria - Archaea - Fungi - Protozoa - Algae - Small multicellular animals Schwann Formulated the cell theory What was first classified as a separate group of prokaryotes in 1977 by Carl Woese and George E. Fox in phylogenetic trees based on the sequences of ribosomal RNA (rRNA) genes Archaea Bacteria and Archaea - Unicellular and lack nuclei - Much smaller than eukaryotes - Found everywhere there is sufficient moisture - Reproduce asexually - Two kinds * Bacteria - cell walls contain peptidoglycan * Archaea - cell walls composed of polymers other than peptidoglycan, extremophiles Fungi - Eukaryotic (have membrane-bound nucleus) - Obtain food from other organisms - Possess cell walls - Include * Molds - multicellular; grow as long filaments; reproduce by sexual and asexual spores * Yeasts - unicellular; reproduce by budding or sexual spores Protozoa - Single-celled eukaryotes - Similar to animals in nutrient needs and cellular structure - Live freely in water; some live in animal hosts - Asexual (most) and sexual reproduction - Most are capable of locomotion by * Pseudopodia * Cilia * Flagella Algae - Unicellular or multicellular - Photosynthetic - Simple reproductive structures - Categorized on the basis of pigmentation, storage products, motility (e.g. Dinoflagellates) and composition of cell wall Are algae pathogenic? Rare Algae Scientists searched for the answers to which 4 questions? - Is spontaneous generation of microbial life possible? - What causes fermentation? - What causes disease? - How can we prevent infection and disease? Does Microbial Life Spontaneously Generate? Some philosophers and scientists of the past thought living things arose from three processes: - Asexual reproduction - Sexual reproduction - Nonliving matter Spontaneous generation the theory that living things arise from non-living things - Aristotle proposed spontaneous generation Francesco Redi (Italian Physician) 1668 - experiments attempting to disprove spontaneous generation Redi's Experiment When decaying meat was kept isolated from flies, maggots never developed Meat exposed to flies was soon infested As a result, scientists began to doubt Aristotle's theory The Scientific Method Spontaneous generation debate led in part to scientific method: 1. Observation leads to question 2. Question generates hypothesis 3. Hypothesis is tested through experiment(s) 4. Results prove or disprove hypothesis - Accepted hypothesis leads to theory/law - Reject or modify hypothesis John Needham's Experiments (1745) - Scientists thought microbes, but not animals, could arise spontaneously - Needham's experiments reinforced this idea - Spontaneous generation for small organisms again gained favor when John Needham showed that if a broth was boiled (presumed to kill all life) and then allowed to sit in the open air, it became cloudy. What mistake did Needham make? He failed to realize that he didn't boil the gravy long enough to kill the microorganisms that were living in it. Spallanzani's Experiments (1799) Gravy is boiled > Flask is open > Gravy contains microorganisms Gravy is boiled > Flask is sealed > Gravy is free of microorganisms. Conclusions: - Needham failed to heat vials sufficiently to kill all microbes or had not sealed vials tightly enough - Microorganisms exist in air and can contaminate experiments - Spontaneous generation does not occur - Critics argued against experiments * Sealed vials did not allow enough air for organisms to survive * Prolonged heating destroyed "life force" Pasteur's experiments with swan-neck flasks (1859) How does infectious disease arise? "Miasma" - bad air- arises from diseased or decaying bodies "malaria" comes from 'mala aria' (bad air) Louis Pasteur proposed that... germs cause infectious disease In 1862 __________ formulated the Germ Theory of Disease, which states.... Louis Pasteur - microorganisms invade other organisms to cause disease Where do living things come from? How does infectious disease arise? What insights did addressing these questions provide? New information about the nature of living things > spontaneous generation discredited New information about the nature of infectious disease > germ theory of disease proposed Robert Koch sets principlesto identify germs that cause disease Studied anthrax in cattle and sheep Formulated Koch's postulates (1876) Still used today to prove that an organism is associated with a disease E.g., Helicobacter pylori and peptic ulcer disease Koch's Potulates Postulate 1: The same microorganisms are present in every case of the disease Postulate 2: The microorganisms are isolated from the tissues of a dead animal, and a pure culture is prepared. Postulate 3: Microorganisms from the pure culture are inoculated into a healthy, susceptible animal. The disease is reproduced. Postulate 4: The identical microorganisms are isolated and recultivated from the tissue specimens of the experimental animal. Who developed pure culture techniques? Koch What did Koch add to broth liquid medium to develop a solid growth media? Gelatin Semmelweis - Hungarian obstetrician- studied childbed fever during labor/delivery- - 1847 - suggested transmission by surgeons after autopsies - hand washing in chlorine water could interrupt transmission of disease Lister - surgeon working in England - 1865 - initiated use of dilute carbolic acid on bandages and surgical instruments- pioneered use of aseptic technique in surgery Florence Nightingale founder of modern nursing John Snow founder of infection control and epidemiology because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854. Edward Jenner vaccine (Small Pox from Cow Pox)- field of immunology Edward Jenner-Vaccination Paul Erlich "magic bullets" - field of chemotherapy (first effective medicinal treatment for syphilis, thereby initiating and also naming the concept of chemotherapy.) What key advances fostered the development of Microbiology? 1) invention of the microscope 2) spontaneous generation discredited 3) germ theory of disease 4) Koch's postulates - used to prove a specific microbe causes a particular disease 5) culture of microbes in the laboratory 6) work toward controlling infections Who invented Gram Staining Hans Christian Gram Gram staining - Involves the applications of a series of dyes - Some microbes are left purple, now labeled Gram-positive - Other microbes are left pink, now labeled Gram-negative - Gram procedure used to separate into two groups Who discovered Penicillin? Alexander Fleming Immunization and host response Immunology Discovery of viruses Virology Discovery and use of antibiotics and chemotherapy antimicrobial agents Discovery of DNA as the genetic material bacterial genetics Griffith's experiment mice are injected with dead bacteria of one strain and live bacteria of another, and develop an infection of the dead strain's type. What did Avery, MacLeod, and McCarty discover about microbial genetics? genes are contained in molecules of DNA What did Beadle and Tantrum discover? - a gene's activity is related to protein function - Translation of genetic information into protein explained - Rates and mechanisms of genetic mutation investigated - Control of genetic expression by cells described Genetic sequencing purposeful manipulation of genetic material to change the characteristics of an organism What are current challenges in microbiology? 1. Genetic engineering 2. Genome sequencing 3. Emerging and re-emerging infections 4. Antibiotic resistance 5. Bioterrorism Bioterrorism intentional or threatened use of microbes to cause fear or disease Bioremediation use of microorganisms to detoxify substances in the environment Bacterial growth can be increased by applying fertilizers, which ... increase the availability of nitrogen and phosphorus, the nutrients bacteria need to utilize hydrocarbons as a food source. Wastewater Disposal of sludge (semisolid waste) = Biogas (Methane gas) Common properties of all living things 1. Order: all organisms exhibit complex organization 2. Regulation: regulatory mechanisms maintain an organism's internal environment within limits that sustain life 3. Growth and Development: each organism has a pattern of growth and development characteristic of its species 4. Energy Utilization: organisms take in energy and transform it to perform all of life's activities. 5. Response to the environment: all organisms respond to environmental stimuli 6. Reproduction: DNA lends itself to precise replication, and all organisms reproduce their own kind 7. Evolution: species have the capacity to change and evolve over time Structure = Function Cell Theory All living things are composed of cells and can be categorized on the basis of their cell structure as: Prokaryotes (prokaryotic) Eukaryotes (eukaryotic)