Microbiology long quiz reviewer

• Microbiology


  The study of microbes
• Microbe


  Minute living things too small to be seen with the unaided eye, single celled or multicellular, viewed by using a microscope, ubiquitous
• Germ


  Rapidly growing cell that causes disease
• Significance of microbes


  • Nutrient production and energy flow (photosynthesis, nitrogen cycle, oxygen production)
  • Decomposition
  • Bioremediation
  • Cause disease (production of vaccines)
  • Production of food (vinegar, cheese, bread)
  • Production of drugs e.g. insulin
• Microbiota/Human microbiome


  Microbes that live in the human body (doesn't give diseases)
• Pathogens


  Microbes that cause diseases
• Microbial Culture


  Collection of cells that have been grown in/on a nutrient medium
• Culture medium


  Solid or liquid mixture that contains nutrients in order for the microorganism to grow
• Colony


  Single microbial cell that grows/divides/proliferates
• Types of microbiota


  • Normal microbiota
  • Transient microbiota
  • Resident microbiota
• Normal microbiota are the microorganisms that inhabit the skin and mucous membrane of healthy persons, they are the first line of defense against pathogenic microorganisms, assist in digestion, play a role in toxin degradation
• Transient microbiota are microbes that are just passing through, they may attempt to colonize the same areas of the body as do resident microbiota but are unable to remain in the body for extended periods of time due to difficulty competing with established resident microbes
• Resident microbiota inhabits your body permanently
• Taxonomy


  • Classification
  • Description
  • Identification
  • Naming of living organism
• In 1758, Carolus Linnaeus categorized organisms into 3 kingdoms: Plants, Animal, Mineral. Mineral was later abandoned
• In 1866, Ernst Haeckel categorized into 4 kingdoms: Animals, Plants, Protists, Monera
• In 1969, Robert Whittaker added a fifth kingdom: fungi
• Domains of life


  • Bacteria (cell walls contain peptidoglycan)
  • Archaea (cell walls lack peptidoglycan)
  • Eukarya (Protists, Fungi, Plants, Animals)
• Nomenclature


  A two-word naming system for identifying organisms by genus and species
• Genus


  First name, always capitalized
• Species


  Second name, not capitalized
• Scientific names are either underlined or italicized, e.g. Staphylococcus aureus
• Bacteria are unicellular prokaryotes with no nucleus, a variety of shapes, cell walls containing peptidoglycan, and reproduce by binary fission
• Archaea are also prokaryotes but their cell walls lack peptidoglycan, and they are typically found in extreme environments
• Fungi are eukaryotes that absorb organic material from the environment, can be unicellular or multicellular, cannot carry out photosynthesis, have cell walls composed of chitin, and reproduce sexually or asexually
• Viruses are very small, acellular, and inert outside of a host, containing DNA or RNA surrounded by a protein coat sometimes enclosed by a lipid membrane, and use the cellular machinery of a host to reproduce
• Protozoa are unicellular eukaryotes that move using pseudopods, cilia or flagella, obtain energy and carbon dioxide through photosynthesis, and reproduce sexually or asexually
• Algae are photosynthetic eukaryotes with a wide variety of shapes, cell walls composed of cellulose, and require water, light, carbon dioxide, oxygen and carbohydrates
• Robert Hooke first looked at thin slices of cork and saw individual cells, formulating the cell theory that all living things are made of cells
• Anton van Leeuwenhoek made better microscopes than Hooke and was the first to see and draw detailed observations of living microbes he called "animalcules"
• The theory of spontaneous generation, that microorganisms can arise from non-living matter, was disproven by experiments of Francesco Redi, John Needham, and Lazzaro Spallanzani
• Louis Pasteur's swan-neck flask experiment demonstrated that air may contain microbes that can contaminate broth, disproving spontaneous generation
• Pasteur discovered that yeasts convert sugars into alcohol in the absence of oxygen, a process called fermentation, and developed pasteurization to kill spoilage bacteria in beer, wine and milk
• Aseptic technique involves practices and procedures to prevent contamination from pathogens, used by healthcare workers to minimize infection risk
• Sanitizing removes bacteria from surfaces, disinfection kills bacteria/viruses on surfaces, and sterilization kills every microorganism
• Joseph Lister pioneered antiseptic surgery using phenol (carbolic acid) to reduce infections and deaths
• Koch's Postulates


  • Organism must always be present in every case of disease
  • Organism must be isolated from a host containing the diseases and grown in pure culture
  • Samples of the organism taken from pure culture must cause the same disease when inoculated into a healthy animal in the Lab
  • The organism must be isolated from the inoculated animal and must be identified as the same original organism that was first isolated from the originally diseased host
• Koch's Postulates have limitations as they are only applicable to few infectious diseases, fail to explain prion diseases, and the animal used may not develop the disease due to asymptomatic carriage, natural immunity or genetic resistance
• Edward Jenner inoculated an 8-year-old volunteer with cowpox, and after recovery the volunteer never got sick with cowpox or smallpox again, leading to the development of vaccines
• Pasteur found that bacteria that causes cholera lost its virulence (ability to cause disease) after being grown in the laboratory, and inoculating subjects with this avirulent bacteria developed immunity to the virulent form