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159 Cards in this Set
- Front
- Back
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microbes/microorganisms
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minute living things that individually are usually too small to be seen with the unaided eye
ex: bacteria, fungi (yeasts and molds), protozoa, and microscopic algae, viruses |
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viruses
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noncellular entities sometimes regarded as stradling the border between life and nonlife
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soil microbes
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help breakdown wastes and incorprate nitrogen gas from the air into organic compounds
->recycle chemical elements between soil, water, life, and air |
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photosynthesis
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food and oxygen generating process that is critical to life on Earth
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pathogenic
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disease-producing
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Carolus Linnaeus
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nomenclature for organisms established in 1735
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genus
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first name and is always capitalized
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specific epithet
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species name, follows genus and is not capitalized
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bacteria
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relativly simple, single-celled (unicellular) organisms
-genetic material not enclosed in special nuclear membrane -bacteria cells= prokaryote -enclosed in cell walls -reproduce by binary fission -swim by using flagella |
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bacterial cell shapes
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-bacillus (rodlike)
-coccus (spherical/ovical) -spiral(corkscrew/curved) |
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bacteria nutrition
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organic chemicals-->derived from dead/living organisms in nature
-photosynthesis |
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archaea
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-prokaryotic cells
-cell walls lack peptidoglycan -extreme environments -not known to cause diseases on humans |
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3 main groups of archaea
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methanogens
extreme halophiles extreme thermophiles |
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methanogens
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produce methane as a waste product from respiration
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extreme halophiles
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halo=salt
philic=loving live in extremely salty environment (ex: Great Salt Lake, Dead Sea) |
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extreme thermophiles
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live in hot sulforous water, such as hot springs at Yellowstone
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fungi
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eukaryotes
unicellular or multicellular cell wals composed primarly of chitin yeasts molds reproduce sexually/asexually |
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eukaryotes
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organisms whose cells have a distinct nucleus containing the cells genetic material (DNA) surrounded by a special envelope called the nuclear membrane
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yeasts
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unicellular forms of fungi
oval microorganisms that are larger than bacteria |
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molds
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visible masses of mycelia-->composed of long filaments (hyphae) that branch and intertwine
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nourishment for fungi
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solutions of organic material from their environment
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slime molds
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have characteristics of both fungi and amoebas
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protozoa
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unicellular eukaryotic microbes
move by pseudopods (extensions of cytoplasm) free entities/parasites absorb/ingest organic compounds parasites reproduce sexually/asexually |
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algae
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photosynthetic eukaryotes with a wide variety of shapes
-sexual and asexual reproductive forms -cell walls normaly composed of cellulose -abundant in fresh and salt water, soil, association with plants -photosunthesizers -produce oxygen and carbon dioxide |
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photosynthesizers
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need light, water and carbon dioxide for food production and growth
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viruses
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most only seen with electron microscope
acellular (not cellular) structurally simple: core and protein coat reproduce only by using cellular machinery of other organisms |
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core
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one type of nucleic acid-> DNA/RNA
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helminths
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flatworms and roundworms
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carl woese
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classification of microorganisms
1978 system of classification based on cellular organization or organisms |
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robert hooke
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observing thin slice of cork
cell theory |
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cell theory
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all living things are composed of cells
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Anton Van Leewenhoek
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1673-1723
first to observe live microorganisms thru magnifying lenses |
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spontaneous generation
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forms of life could arise spontaneously from nonliving matter
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francesco redi
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1668
demonstrate maggots did not arise spontaneously from decaying meat experiment= 2 jars one left unsealed, other sealed unsealed jar let flies lay eggs on meat and hatch into larvae other jar sealed unable to produce larvae |
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Spallanzani
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proved that nutrient fluids heated after being sealed in a flask did not develop microbial growth
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biogenesis
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living cells can arise only from preexisting living cells
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louis pasteur
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1861
experiment: several shortnecked flasks with beef borth then boil, some allowed to cool-->contamination with microbes when left open, other sealed was free of microbes -later s-shaped flask boiled and cooled and broth did not decay altho air passed into flask (curved neck trapped airborne microorganisms) showed that microorganisms can be present in nonliving matter- solids, liquids, air -microbial life destroyed by heat |
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aseptic techniques
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techniques that prevent contamination by unwanted microorganisms
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golden age of microbiology
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1857-1914
rapid advances, spearheaded by Pasteur and Robert Koch led to establishment of microbio as a science -studied chemical activities of microorganisms, improved techniques for performing microscopy and culturing microorganisms and developed vaccines and surgical techniques |
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paul ehrlich
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started chemotherapy revolution
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alexander fleming
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penicillin (anitbiotic produced by a fungus)
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bacteriology
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study of bacteria
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mycology
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study of fungi, includes medical, agricultural and ecological branches
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parasitology
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study of protozoa and parasitic worms
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genomics
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study of all of an organism's genes
-classify bacteria and fungi according to there genetic relationships with other bacteria, fungi, and protozoa |
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immunology
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study of immunity
-began with Jenner's first vaccine 1796 |
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interferons
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substances generated by body's own immune system
-inhibit replication of viruses |
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serotypes
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variants within a species
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Rebecca Lancefield
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1933
streptococci classified by serotypes based on componenets in cell walls of bacteria |
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virology
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study of viruses
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Wendell Stanley
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1935
study of viral structure and chemistry |
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recombinant DNA
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hybris resulting from fragments of human/animal DNA (genes) that code for IMP proteins can be attached to bacterial DNA
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Paul Berg
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1960s
recombinant DNA |
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microbial genetics
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studies the mechanisms by which microorganisms inherit traits
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molecular biology
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studies how genetic info is carried in molecules of DNA and how DNA directs synthesis of proteins
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messenger RNA
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chemical involved in protein synthesis
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Beijerinck and Winogradsky
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first to show how bacteria help recycle vital elements btwn soil and atmosphere
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microbial ecology
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study of the relationship btwn microorganisms and their environment
-branched to include study of how microbial populations interact with plants and animals in various environments |
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sewage treatment
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using microbes to recycle water
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bioremediation
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using microbes to clean up pollutants
some bacteria use pollutants as energy souces; others produce enxymes to break down toxins into less harmful substances -toxins can be removed from underground wells, chemical spills, toxic waste sites, and oil spills |
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bacillus enzymes
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used in household detergents to remove spots from clothing
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insect pest control by microorganisms
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using microbial rather than chemical insect control, farmers avoid harming environment
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biotechnology
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commercial use of microorganisms to produce practical applications (common foods and chemicals)
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gene therapy
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inserting a missing gene/replacing a defective on in human cells
-uses harmless virus to carry missing/new gene into certain host cells-->gene picked up and inserted into appropriate chromosome |
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normal microbiota/flora
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variety of microorganisms on and inside our bodies
-they do not harm us -some can protect against disease by precenting overgrowth of harmful microbes -some can produce useful substances ex: vitamin K and some B vitamins -when some leave habitat can cause disease |
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resistance
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ability to ward off diseases
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biofilms
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microorganisms that attach to eachother and/or some usually solid surface
-complex aggregation of microbes |
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infectious diseases
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a disease in which pathogens, invade a susceptible host, such as a human/animal
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emerging infectious diseases (EIDs)
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number of new diseases that are new/changing and are increasing/have ptoetnial to increase in near future
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contributing factors to EIDs
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evolutionary changes in exisitng organisms
-spread of known diseases to new geographic regions/populations by modern transport -increase human expoure to new unusual infections agents at areas undergoing ecologic changes (ex: deforestation and construction) -antimicrobial resistance |
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avian influence A (H5N1)
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-wild birds spread influenza to domesticated birds-virus causes death
-substance normally specific to certain species-can crossover however |
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West Nile enchaphilitis (WNE)
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inflammation of the brain caused by West Nile Virus
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bovine spongiform encephalopathy (BSE/Mad cow disease)
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caused by prion (infecitous protein)
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meter (m)
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standard unit of length in metric system
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micrometer
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10-6 m
micro divide by 1 million |
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nanometer (nm)
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10-9 m
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ocular lens 9eyepiece)
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remagnifies the image formed by the objective lens
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body tube
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transmits thei mage fromt he objective lens to the ovular lens
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objective lenses
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primary lenses that magnify the specimen
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stage
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holds the microscope slide in position
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condenser
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focuses light thru specimen
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disphragm
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controls the amount of light entering the condenser
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illuminator
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light source
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light microscopy
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the use of any kind of microscope that uses visible light to observe specimens
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compound light microscopy
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series of lenses and uses visible light as its source of illumination
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total magnification
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multiplying the objective lens magnification (power) by the ocular lens magnification (power)
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resolution
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resolving power
ability of the lenses to distinguish fine detail and structure -specifically, distinguish 2 points a specified distance apart *shorter wavelength of light used in instrument, greater the resolution |
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cystic fibrosis
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biolfilm forming P. aerugina bacteria colonize the lungs of cystic fibrosis patients
-leading cause of death in these patients |
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myxobavteria
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found in decaying organic material and fresh water
-cells appear to hunt in packs |
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vibrio
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bioluminescent bacterium that lives as a symbiant in light-producing organ of squid and certain fish
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quorum sensing
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cell density alters gene expression in bacterial cells
-ability of bacteria to communicate and coordinate behavior |
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medium
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substance in which specimens are suspended
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refractive index
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measure of the light-bonding ability of a medium
-increase contrast -stain -light rays change direction (refract) from a straight path by bending/changing angle at the coundry btwn materials and increase image's contrast btwn specimen and medium |
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darkfield microscope
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used to examine live microorganisms that either are invisible in the ordinary light micrscope, cannot be stained by standard methods, or are so distorted by staining that their characteristics cannot be identified
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opaque disk
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blocks light that would enter objective lens directly
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phase-contrast microscope
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permits detailed examination of internal structures in living microorganisms
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in phase
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peaks and valleys match of light rays
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reinforcement
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relative brightness when wave peak of light rays from one source matches light rays from another
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interference
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relative darkness when wave peak and wave trough from another suce coincide
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diffraction
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scattering of light rays as they "touch" a specimen's edge
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differential interference contrast (DIC) microscopy
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uses differences in refractive indexes with 2 beams of light
-prisms split each light beam-contrasting colors, 3D |
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staining
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coloring the microorganisms with a dye that emphasizes certain strutures
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fixed
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attached to micrscopic slide
-kills the microorganisms |
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smear
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thin film of material containing microorganisms that is spread over surface os slide
-air dry |
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stains
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salts composed of a positive and negative ion, one is colored-chromophore
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basic dyes
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color is in positive ion
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acidic dyes
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color is in negative ion
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negative staining
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preparing, colorless bacteria against a colored background
-observe overall cell shapes, sizes, and capsules |
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2 types of staining techniques
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simple
differntial special |
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simple staines
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aqueous/alcohol solution of a single basic dye
purpose: highlight the entire microorganism so that cellular shapes and basic structures are visible |
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mordant
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a chemical that is added to the soltuion to intensify the stain
-increases affinity of a stain for a biological specimen -coat a structure (flagellum) to make it thicker and easier to see after stained |
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differential stains
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react differently with different kinds of bacteria and can be used to distinguish them
-ex; gram and acid-fast stain |
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gram stain
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1884 classifies bacteria into 2 larfe groups: gram-positive and gram-negative
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gram stain procedure
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1. application of crystal violet (purple dye)
2. application of rodine (mordant) 3. alcohol wash (decolarization) 4. application of safranin 9counterstain) |
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primary stain
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stain imparts its color to all cells
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decolarizing agent
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removes primary stain from cells of some species but not from others
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gram-positive bacteria
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bacteria that retain primary stain even after alcohol has attempted to decolarize them
disaccharides and aa cell wall generally killes easily by penicillins and cephalospores |
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gram-negative bacteria
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bacteria that lose color after decolarization
layer of lipids and polysaccharides cell wall |
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counterstains
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stains that have a contrasting color to primary stain
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acid-fast stain
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binds strongly only to bacteria that hvae a waxy material in their cell walls
-used to ID all bacteria in genus mycobacterium ex: tuberculosis and leprosy |
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special stains
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used to color and isolate specific parts of microorganisms such as endospores and flagella and to reveal the presence of capsules
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capsule
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gelatinous covering on many microorganisms
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virulence
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degree to which a pathogen can cause disease
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negative staining for capsules
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-capsular materials are soluble in water (may be dislodged/removed during washing)
-capsules do not accept most stains, the capsules appear as unstained halos around bacteria cells -stand out against a contrasting background |
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endospore staining
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special resistant, dormant structure formed within a cell that protects bacterium from adverse environmental conditions
-heat helps stain penetrate endospore wall -highly refractive |
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bacterial flagella
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structures of locomotion too small to be seen with a light microscope without staining
-build up diameters of flagella until visible under light microscope |
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biolfilms
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reside in a matrix made up primarily of polysaccharides but also containing DNA and proteins (often informally called slime)
-biological systems -usually attached to a surface -form pillar-like structures |
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hydrogel
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a complex polymer containing many times its dry weight in water
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quorum sensing
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cell-to-cell chemical communication which allows bacteria to coordinate their activity and group todether into communities that provide benefits not onlike those of multicellular organisms
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nosocomial infections
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infections acquired in health care facilities
-most caused by biofilms on medical catheters |
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culture medium
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nutrient material prepared for the growth of microorganisms in a laboratory
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inoculum
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microbes that are introduced into a culture medium to initiate growth
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culture
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microbes that grow and multiply in or on a culture medum
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criteria for culture medium to grow a culture
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-contain right nutrients for the specific microorganism wanted to grow
-sufficient moisture -properly adjusted pH -incubated at proper temp -suitable level of oxygen |
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sterile
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culture medium must initially contain no living microorganisms so that the culture will contain only the microbes and their offspring that we add to the medium
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agar
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a solidifying agent and is a complex polysaccharide derived from a marine alga
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slants
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test tubes that are allowed to solidify with the tube held at an angle so that a large surface area for growth is available
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deep
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when agar solidifies in a vertical tube
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Petri dishes
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shallow dishes with a lid that rusts over the bottom to prevent contimination
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petri (culture) plates
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when petri dishes are filled
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chemically defined medium
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one whose exact chemical composition is known
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fastidous
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organisms that require many growth factors
ex; Lactobacillus sometimes used in tests that determine concentration of a particular vitamin in a substance |
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complex media
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made up of nutrients including extracts from yeasts, meat, plants, digests of proteins from these and other sources
-exact chemical composition varies, slightly from batch to batch |
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protein
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a large, relativly insoluble molecule that am inority of microorganisms can utilize directly
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peptones
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shorter chains of amino acids
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nutrient agar
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when agar is added to nutrient broth
-agar itself is not a nutrient |
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reducing media
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contain ingredients, such as soelium, thioglycolate, that chemically combine with dissolved oxygen and deplete the oxygen in the culture medium
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carbon dioxide incubators
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grow aerobic bacteria that require concentrations of CO2 higher/lower than that found in the atmosphere
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candle jars
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large sealed jar containing a lighted candle, which consumes oxygen--> high carbon dioxide levels
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capnophiles
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microbes that grow better at high carbon dioxide concentrations
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selective media
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designed to suppress the growth of unwanted bacteria and encourage the growth of the desired microbes
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bismuth sulfite
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inhibits gram-positive bacteria and most gram-negative intestinal bacteria
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differential media
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make it easier to distinguish colonies of the desired organism from other colonies growing on the same plate
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enrichment culture
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medium is usually liquid and provides nutrients and environmental conditions that favort he growth of a particular microbe but not others
-selective -designed to increase small numbers of the desired type of organism to detectable levels |
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colony
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arises from single spore/vegetative cell or from a group of the same microorganisms attached to one another in clumps/chains
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pure cultures
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clones
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streak plate method
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a sterile innoculating loop is dipped into a mized culture that contains more than one type of microbe and is streaked in a pattern over the surface of the nutrient medium
-as pattern traced, bacteria rub off the loop onto the medium -organism needs to be present in large nubers |
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deep-freezing
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pure culture of microbes placed in suspending liquid and quick-frozen at temps ranging from
-50 degrees c--95degrres c |
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lyophilization
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freeze-drying
suspension of microbes quickly frozen at tmep ranging from -54 to -72 degrees celsius and water removed by a high vacuum (sublimation) |
