Chapter 1 Flashcards
Cell membrane (general)
Barrier that seperates the inside of the cell from the outside environemtn
Cell wall (general)
present in most microbes, confers structural strength
cytoplasm (general)
fluid that fills cells (water, solutes, enzymes)
Genetic material (general)
ds DNA in all cells, stores information for structure of all cells proteins
Ribosomes (general)
all cells, sites of protein synthesis
RNA (general)
all cells, 3 types play role in protein synthese, 1 type in genetic regulation
Domain Bacteria
Usually single celled. Majority have cell wall with peptidoglycan. Lack a memebrane bound nucleus. Ubiquitous and some live in extreme environments. Cyanobacteria and some others produce amounts of significant oxygen.
Domain Archaea
Distinguished from Bacteria by unique rRNA sequences. Lack peptidoglycan in cell walls. Have unique membrane lipids. Some have unusual metabolic characteristics. Many live in extreme env.
Domain Eukarya
Protists- generally larger than Bacteria and Archaea
Fungi- chemohetereotroph absorbs
Acellular Infectious Agents
Viruses
smallest of all microbes, requires host cell to replicate, cause range of diseases, some cancers
Acellular Infectious Agents
Viroids and Virusoids
Infectious agents composed of RNA
Acellular Infectious Agents
Prions
infectious proteins
Antony van Leeuwenhoek
first person to observe and describe microorganisms accurately
Spontaneous generation
living organism can develop from nonliving or decomposing matter
Louis Pasteur
Placed nutrient solutions in flasks. Created flasks with long, curved necks. Boiled the solutions. Left flaaks exposed to air. Results= no growth of microorganisms.
Also demonstrated that alcohol fermentations and other fermentations were the result of microbial activity. Showed that the pebrine disease of silkworms was caused by a protozoan. Developed the process of pasteurization to preserve wine during storage, developed vaccines for chicken cholera, anthrax, and rabies
John Tyndall
demonstrated that dust carries microorganisms, showed that if dust was absent, nutrient broths remained sterile, even if directly exposed to air, also provided evidence for the existence of exceptionally heat resistant forms of bacteria
Germ theory
Belief that certain diseases were caused by microrganisms, not immediately obvious,
Joseph Lister
provided indirect evidence that microorganisms were the casual agents of disease, system of surgery designed to prevent microorganisms from entering wounds as well as methods for treating instruments and surgical dressings, his patients had fewer postoperative infections
Robert Koch
relationship bw Bacillus anthracis and anthrax, mycobacterium tuberculosis and tuberculosis
Koch’s Postulates
The microbes must be present in every case of the disease but absent from healthy individuals. The suspected microbes must be isolated and grown in a pure culture. the same disease must result when the isolated microorganism is inoculated into a healthy host. Isolated again from the diseased host.
Limitations to Koch’s postulates
Some organisms cannot be grown in pure culture. Using humans in completing the postulates is unethical.
