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91 Cards in this Set
- Front
- Back
What are the characteristics that are used to classify (identify) bacteria?
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..
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What are the 3 shapes of bacterial cells?
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Cocci, rods and spiral
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What is an obligate intracellular pathogen?
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A pathogen that must live within a host cell.
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Define: obligate aerobe
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Strict bacterial aerobes requiring O2
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Define: microaerophile
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Bacteria that need a reduced amount of O2
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Define: obligate anaerobe
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Strict bacterial anaerobes that are killed by O2
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Define: aerotolerant anaerobe
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Bacteria that don't need O2, but won't be killed by it either
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Define: facultative anaerobe
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Anaerobes that can use O2, but can also live with or without it
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How are Rickettsia, Chlamydia & Mycoplasams different?
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Chlamydia lack enzymes to produce ATP. Richettsia have a leaky cell membrane. Mycoplasms lack a cell wall
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Which are obligate intracellular pathogens and why?
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Chlamydia & Rickettsia must live within a host cell.
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What are 6 most common elements found in biological molecules?
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Carbon, Hydrogen, Oxygen Nitrogen, Phos, Sulfur
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What is the pH scale?
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The amount of H+ (hydrogen Ion's in a solution or substance.
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What does high pH mean?
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Alkeline (base)
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What does low pH mean?
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Acid
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What is neutral?
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7 H+ = OH-
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Define: carbohydrate
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Biomolecules composed of C, H, O. Ex: monosaccharide, disaccharide, polysaccharide
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Define: monosaccharide
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One sugar ring carbohydrate in bacteria. Function is to breakdown to make ATP. Also called sugars.
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Define: disaccharide
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Two sugar ring carbohydrate in bacteria. Function is to breakdown to make ATP. Also called sugars
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Define: sugars
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The simplest charbohydrate
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Define: polysaccharide
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Many sugar ring carbohydrate in bacteria. Function is structural. Ex: peptidoglycan
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Proteins are polymers of what smaller molecule?
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Amino Acids
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What influences the 3-D shape of the protein?
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The attraction & repulsion between R groups in the protein chain.
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Why is the 3-D shape important?
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The shape allows the protein to perform it's function.
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What are enzymes?
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Protein molecules produced by living cells as "instructed" by genes on the chromosomes.
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Why are enzymes important to cell survival?
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Enzymes make chemical reactions occur in a cell to produce a product.
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What does "ase" at end of word imply?
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It is an enzyme
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What are 4 possible consequenses of an altered enzyme 3-D shape?
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1. No change in function or shape 2. Change in shape resulting in protein not working 3. Protein works better 4. Protein won't fit old substrate, but fits new one
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What is DNA and RNA?
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Nucleic acids or biomolecule in living cells
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What is the structure and function of DNA?
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Double stranded, contains deoxyribose & thymine. Contains information used to construct enzymes
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What is the structure and function of RNA?
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Single stranded, contains ribose & uracil. Contructs a cells enzymes
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What is a gene?
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A section of DNA that holds information on the amino acid sequence of a protein.
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What is a mutation?
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A change in a gene's nitrogenous base sequence. Mutations are frequent in bacteria due to high rate of cell reproduction.
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How does the nucleotide sequence of a gene influence the protein for which the gene codes?
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The nucleotide is made of amino acids in a specific order. One change alters the amino acid sequence.
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What do exoenzymes do vs. endoenzymes
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Made by cell, catalyst of reactions (ex: outside) or (endo: inside) the body.
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3 factors that influence how well an enzyme works
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Temperature, pH, Presence of enzyme inhibitors
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How does temperature decrease the enzyme's activity?
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It's shape is altered by temp. High temp it will denature or become straight. Low temp won't cause shape change, but stop activity until warmed.
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How does pH decrease the enzyme's activity?
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Every enzyme has an optimum pH level based on where the organism lives. Human pathogens have pH of 7.35-7.45
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How does presence of enzyme inhibitors decrease the enzyme's activity?
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A molecule binds on enzyme so that substrate can't bind & a chemical reaction won't occur
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What is "activity"?
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The rate an enzyme can convert substrate to product. High activity=fast product production. Low activity=slow product production
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What are enzyme inhibitors?
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Physical or chemical means of preventing enzyme growth
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How can certain inhibitors help us treat a bacterial infection?
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They stop certain critical reactions from happening.
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What does Sulfanilamide do? (sulfa drugs)
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Inhibit production of folic acid in bacteria
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What bacterial enzyme does penicillin inhibit?
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Cell wall synthesis
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What is penicillinase? Who makes it?
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A penicillin resistant enzyme made by bacteria
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How does penicillinase work & who benefits from it?
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They destroy the B-lactam ring in penicillins. An organisim that produces penicillinase.
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What is augmentin (what does it contain)?
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Drug combination of B-lactim antibiotic & B-lactamase inhibitor
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How does augmentin work against PCN resistant bacteria?
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B-lactam inhibitor binds to & inactivates the B-lactamse allowing antibiotic to enter bacterial cell and disrupt cell wall synthesis.
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Define: metabolism
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All of the chemical reactions that occur in a cell. Two types: Catabolic & Anabolic
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Define: catabolism
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Series of chemical reactions that breakdown food molecules, extracting energy & using it to make ATP for the cell
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Define: anabolism
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Reactions to make all structures for cell growth that require ATP
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Example of catabolic process
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Glycolysis
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Example of anabolic process
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Photosynthesis
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What is ATP?
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Adenosine triphosphate - picks up energy from catabolic path & delivers to anabolic path.
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Why is ATP important to cell?
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They transfer energy from energy yielding molecules to energy required molecules
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What is a "high energy bond"?
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Temporary storage for energy in special molecules
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3 primary ways bacteria get their energy from food?
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Aerobic cell respiration, Anaerobic cell respiration, Fermentation
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Aerobic cell respiration process (is O2 required, smaller pathways, ATP yield, waste)
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Requires O2 * Major pathway * 38 ATP * Glucose waste
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Anaerobic cell respiration process (is O2 required, smaller pathways, ATP yield, waste)
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Doesn't need O2 * Major pathway * 20-30 ATP * Glucose waste
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Fermentation process (is O2 required, smaller pathways, ATP yield, waste)
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Doesn't need O2 * Major pathway * 2 ATP * Glucose waste
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Which metabolic process obligate aerobes/anaerobes/facultative use?
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6 factors affecting Microbial growth
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Temperature, pH, Osmotic environment/pressure, Barometric pressure, Proper nutrients, Proper O2 levels
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Define: thermophiles
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Bacteria growth: HIGH temp Ex: hot spring bacteria
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Define: mesophiles
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Bacteria growth: MID temp Ex: Human pathogens
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Define: psychrophiles
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Bacteria growth: LOW temp Ex: spoilage bacteria in fridge
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Define: temperature range (min/max/optimum)
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Range bacteria will die, stop growing and perfect conditions
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Define: acidophiles
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Bacteria that require LOW pH for growth.
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Define: alkalinophile
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Bacteria that require HIGH pH for growth.
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Define: barophiles
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Bacteria that require HIGH PRESSURE for growth
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Define: halophiles
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Bacteria that require HIGH SALT environment
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Define: haloduric organisms
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Bacteria that tolrate high salt, but don't require it
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What is osmotic pressure?
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Pressure exerted on a cell membrane by solutions inside & outside of the cell
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How does salinity affect bacterial cells?
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By causing the cell to shrink or lyse if too little or too much salt
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How have temp, pH, salt/sugar been used to preserve food & stop spoilage?
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Inhibit the growth of most microorganisms
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Define: sterilization (give example)
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Killing of all forms of life on object by heat, gas (ethylene oxide) or radiation (gamma rays)
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Define: pasteurization (give example)
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Killing of pathogenic bacteria by heating liquid to 72c for 15 seconds
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Define: disinfection (give example)
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Use of chemical agent to kill all vegetative forms of life on objects.
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Define: antiseptic (give example)
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Disinfection of skin or living tissues. Ex: alcohol
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Define: asepsis (give example)
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Preventing unwanted bacteria from entering a particular area. Ex: gown, glove, masks
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Define: germicide/bactericide (give example)
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Chemical agent that rapidly kills germs or bacteria.
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Define: degerming (give example)
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Act of cleansing the skin by washing, scrubbing or use of antiseptic
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Define: sanitization (give example)
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Use of chemicals or scrubbing on utensils, toilets to reduce number of pathogens
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Define: bacteriostatic (give example)
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When bacterial growth & reproduction has been stopped, but not killed
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3 major mechanisms by which microbial growth is controlled by the various agents
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Denature the 3-D shape of microbe, Damage or Destroy the microbe's DNA, Damage microbe's cell membrane or wall
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What are the various physical means of control are e.g. heat, filtration, etc
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Moist heat (steam) @ 100c 10 min kills bacteria, 30 min kills viruses, 20 hrs kills spores. Dry heat takes longer and must be hotter.
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How the concentration of ethanol affects its effectiveness
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Must have H2O to denature the proteins
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How can some organisms survive IN certain disinfectants?
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Gram rod negative can live in disinfectant. Disinfectants effective against gram positive bacteria
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How are some organisms resistant to desiccation?
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They remain viable, but don't reproduce when dry. (Staph aureus)
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What is generation time?
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Amount of time it takes for a cell to grow and divide, E.coli 15 min/TB 13 hrs
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What is incubation periods?
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Proper temp & atmosphere set for bacterial growth inside incubator Ex: TB 3mo-2year
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What is treatment periods?
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Amount of time it takes for treatment to kill bacteria Ex: TB 6mo-1yr
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Short generation time leads to short incubation and short treatment period
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UTI/E.coli: generation 100 cells to millions in 16 hours, incubation 24-72 hrs, treatment 1-2 weeks
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