Microbiology Test – Flashcards
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| Metabolism |
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| The set of controlled chemical reactions within cells |
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| Growth |
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| Increase in the size od a population |
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| Colony |
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| Aggregation of cells arising from a single parent cell |
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| Biofilm |
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| A collection of microbes living on a surface in a complex community |
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| Autotrophs |
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| Organisms that utilize an inorganic source of Carbon (i.e Carbon Dioxide) "feed themselves" |
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| Heterotrophs |
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| Catabolize reduced organic molecules(i.e. proteins, carbs, amino acids, fatty acids that they acquire from other organisms) |
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| Chemotrophs |
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| Organisms that require energy from redox reactions involving inorganic and organic chemicals. |
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| Phototrophs |
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| Organisms that use light as their energy source |
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| Organotrophs |
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| Microorganism that acquires electrons from organic sources |
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| Lithotrophs |
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| Microorganisms that acquire electrons or hydrogen atoms from inorganic molecules |
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| Obligate aerobes |
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| Oxygen is essential |
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| Obligate anaerobes |
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| Oxygen is a deadly poison |
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| Singlet Oxygen |
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| Toxic O2 (white blood cells use it to oxidize pathogens) |
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| Caroteniods |
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| A pigment that prevents toxicity by removing the excess energy of singlet oxygen |
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| Superoxide radical |
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| Toxic O2- ( Superoxide dismutase's are produced to detoxify them- without it the organism will die)Anaerobes do not produce |
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| Peroxide anion |
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| Toxic O2- (makes hydrogen peroxide an antimicrobial agent)-(catalase or peroxidase detoxify) |
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| Hydroxyl radical |
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| Toxic 02-( Most reactive) |
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| Facultative anaerobes (ex. E. Coli) |
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| An aerobic organism that can maintain life via fermentation or anaerobic respiration |
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| Aerotolerant anaerobes (ex. Lactobacilli that transform cucumbers into pickles) |
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| tolerate oxygen by having enzymes that detoxify oxygen's poisonous form |
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| Microaerophiles (ex. H. Pylori ulcer causing pathogen) |
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| Require O2 levels 2%-10% (found in the stomach)and are damaged by the 21% found in the atmosphere |
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| Nitrogen fixation |
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| Reducing nitrogen gas to ammonia ( Very few bacteria are able to do this (ex. cyanobactieria and Rhizibium) |
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| Trace elements |
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| Required in very small amounts |
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| Nitrogen |
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| Growth limiting nutrient for many organisms: Without the nutrient they cannot build proteins and nucleotides |
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| Psychrophiles |
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| Grow best at temps below 15 degrees Celsius, They die at temps above 20 degrees Celsius. Live in snowfields, Ice and cold water. Do not cause disease in humans because of temp. Can cause food spoilage in refrigerators. |
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| Mesophiles |
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| Grow best in 20-40 degrees Celsius. Human pathogens, |
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| Thermoduric |
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| Mesophiles that can survive brief periods at higher temps. |
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| Thermophiles |
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| Grow above 45 degrees Celsius. ( compost piles and hot springs |
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| Hyperthermophiles |
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| Grow in water above 80 degrees Celsius (some up to 135 degrees Celsius. |
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| Neutrophiles |
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| 6.5-7.5 |
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| Acidophiles |
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| Live in mines and in water that runs through mines down to 0 |
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| Alkalinophiles |
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| Live in soil and water up to 11.5 (cholera lives best 9.0) |
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| osmotic pressure |
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| The diffusion of water across a membrane and is driven by unequal solute concentrations on two sides of such a membrane |
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| Crenation |
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| Shriveling of cytoplasm |
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| Obligate Halophiles |
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| Adapted to growth under high osmotic pressure and live in the Great salt late and smaller salt ponds |
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| Facultative Halophiles |
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| ( Staphylococcus Aureus) |
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| S. Aureus |
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| causes pimples, sties, boils, life threatening scalded skin and toxic shock. |
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| Hydrostatic pressure |
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| Water exerts pressure in accordance to depth 1 atm to 10 meters. |
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| Barophiles |
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| Organisms that live under extreme pressure |
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| Synergistic relationship |
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| Each receives benefits better together than they would alone |
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| Symbiotic relationship |
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| They become interdependent on eachother |
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| Biofilm Development |
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| Free living cells 2)Settle on the surface and attach 3)Develop a gooey extracellular matrix and secrete quorum sensing molecules 4)Quorum sensing triggers cells to change their biochemistry and shape 5)New cells arrive possible including new species, and water channels form in the biofilm. 6)Some microbes escape from the biofilm and resume a free living existence , and perhaps form a new biofilm on another surface 3)The slimy matrix adheres the cells together 4) |
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| Inoculum |
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| Sample |
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| Medium |
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| Collection of nutrients |
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| Culture |
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| Microorganisms that grow from an inoculum |
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| colonies |
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| Cultures that are visible on solid media |
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| 1)Environmental specimens |
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| Taken from ponds, streams, soil, air |
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| Clinical specimen |
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| Taken from patients |
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| Normal Microbiota |
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| Microorganisms associated with certain areas of the body without causing diseases |
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| Pure cultures |
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| Cultures composed of cells arising from a single progenitor |
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| axenic |
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| pure culture |
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| CFU |
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| Colony forming unit |
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| Nutrient broth |
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| contains beef extract and peptones |
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| Agar |
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| a complex polysaccharide derived from the cell walls of certain red algae. |
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| Defined media |
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| Exact chemical composition is known |
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| complex media |
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| exact chemical composition is unknown. contains a variety of nutrients |
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| Selective Media |
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| contain substances that either enhance or inhibit growth |
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| Enrichment culture |
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| use a selective medium, and are designed to increase I very small numbers in order to observe them |
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| Cold enrichment |
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| enrich cultures that are cold tolerant |
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| preserving cultures |
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| Normally done by refrigeration |
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| lyophilization |
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| freeze drying |
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| Generation time |
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| The time required for a bacterial cell to grown and divide |
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| logarithmic/exponential growth |
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| any given cell divides to form two cells, and then two divide in four, and then four into eight, and eight into sixteen and so on.... |
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| Growth curve |
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| A graph that plots the number of organisms in a growing population over time |
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| Lag phase |
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| phase in growth curve in which the organisms are adjusting to their enviornment |
