BackFundamentals of Microbiology
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Terms in this set (29)
Microorganisms are organisms too small to be seen with the unaided eye, including bacteria, fungi, protozoa, microscopic algae, viruses, and prions.
Microbes decompose organic waste, form the basis of aquatic food chains, incorporate nitrogen gas into organic compounds, and generate oxygen by photosynthesis.
The microbiome is the community of microbes living stably on or in the human body, helping maintain health, preventing pathogen growth, and training the immune system.
Scientific names use binomial nomenclature: genus (capitalized) and specific epithet (lowercase), italicized or underlined, often Latinized and descriptive or honoring a scientist.
Types include bacteria, archaea, fungi, protozoa, algae, viruses, and multicellular animal parasites.
Bacteria are unicellular prokaryotes with peptidoglycan cell walls, reproduce by binary fission, and may move using flagella.
Archaea are prokaryotes lacking peptidoglycan walls, often live in extreme environments, and are not known to cause human disease.
Fungi are eukaryotes with chitin cell walls, absorb organic chemicals for energy, and include unicellular yeasts and multicellular molds.
Protozoa are eukaryotes that absorb or ingest organic chemicals, may be motile, and reproduce sexually or asexually.
Algae are eukaryotes with cellulose cell walls, found in water and soil, using photosynthesis to produce oxygen and carbohydrates.
Viruses are acellular, consist of DNA or RNA core with a protein coat, and replicate only inside living host cells.
Spontaneous generation is the disproven idea that life arises from nonliving matter; biogenesis states living cells arise only from preexisting cells.
Louis Pasteur demonstrated that microorganisms come from the air, not mystical forces, using S-shaped flasks that kept microbes out but allowed air in.
Pasteur showed microbes cause fermentation, converting sugar to alcohol anaerobically, and spoilage by bacteria turning alcohol to vinegar.
Pasteurization is heating beverages briefly at high temperature to kill harmful bacteria without evaporating alcohol.
Koch's postulates are experimental steps to prove a specific microbe causes a specific disease, established after discovering the anthrax bacterium.
Vaccination, derived from Latin vacca (cow), involves inoculating with a related virus (e.g., cowpox) to provide immunity against diseases like smallpox.
Focus on treating microbial diseases with chemotherapy, including synthetic drugs and antibiotics produced by bacteria and fungi.
Alexander Fleming discovered penicillin in 1928, produced by Penicillium fungus, which kills Staphylococcus aureus.
Biofilms are microbial communities attached to surfaces, which can protect mucous membranes or cause infections and antibiotic resistance.
Factors include microbial evolution (e.g., antibiotic resistance), modern transportation, and increased human exposure to new infectious agents.
Microbes convert organic waste in sewage into by-products like carbon dioxide and nitrates, helping recycle water safely.
Microbes pathogenic to insects, like Bacillus thuringiensis, produce toxins fatal to pests but safe for animals and plants, reducing chemical pesticide use.
Recombinant DNA involves combining DNA from different sources to produce proteins, vaccines, or replace defective genes in gene therapy.
Microbial ecology studies interactions between microbes and their environment, including nutrient cycling of carbon, nitrogen, sulfur, and phosphorus.
The microbiome helps prevent pathogen growth, produces vitamins B and K, and supports immune system function.
Antibiotic resistance occurs when microbes evolve to survive drugs; examples include MRSA and multidrug-resistant Mycobacterium tuberculosis.
The germ theory states that specific microbes cause specific diseases, supported by work from Pasteur, Lister, and Koch.
Normal microbiota colonize the body indefinitely and support health, while transient microbiota colonize temporarily without permanent residence.