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137 Cards in this Set
- Front
- Back
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What are 6 uses of bacteria?
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RACPAD - rDNA, Antibiotics, Chemical Industry, Probiotics, Agricultural, Degradation of toxic waste
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How long are bacteria?
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1-6 Micrometers.
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How wide are bacteria?
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0.2-2.0 micrometers
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Cocci
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spheres
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Bacilli
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rod shaped
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Spirilla
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Spiral shaped
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Vibrios
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comma shaped
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Staph- prefix means....
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Clusters
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What do Prokaryotic cells lack?
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Nuclear membrane, straight chromosomes, multiple chromosomes, histones, organelle, sterols in membrane (except for Mycoplasma), triglyceride fats
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Ribosomes difference btw prok and euk
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Prok is 70s (50s + 30s). Euk is 80s (60s +40s).
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What are the three scientists that have improved the microscope?
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Janssen- combined two lenses. Kepler - improved. Leewenhoek - magnification of 50-300 diameters.
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Name the four types of light microscopes
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Dibs on Flips. Dark field, Brightfield, Flourescence, and Phase contrast. We use bright field compound microscopes in lab
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Electron Microscopes. magnification and name 4 kinds
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100,000x or 0.001 micrometers. TEM - Transmission electron microscope and SEM - Scanning electron microscope. 1,000,000x STM - Scanning tunneling microscope (uses probe with single atom tip ). AFM - Atomic force magnification (gives topographical image).
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Name parts on the cell envelope
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Semipermeable cell membrane. Cell wall - rigid. In gram neg - extra layer - outer membrane
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Cell membrane function
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regulates passage of molecules and ions. also provides rigidity for those who don't have cell walls (Mycoplasma)
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Mycoplasma
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have sterols and no cell wall. Causes atypical pneumonia
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Cell membrane structure
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Bilayer of 60-70% protein. 40-30% lipids.
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What is the main lipid in a cell membrane?
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phospholipid
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What are the differences in phospholipids btw bacteria and archea?
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Glycerol and fatty acids are linked by ESTERs in bacteria. Glycerol and isoprene chains are linked by Ether bonds.
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Intrinsic proteins
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Also called integral. make up 70-80% of membrane proteins. go through membrane
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Extrinsic proteins
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peripheral proteins. found on bilayer. some bind to intrinsic proteins.
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Transport through a cell membrane
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negative charge. passage depends on lipid solubility. large molecules are degraded by hydrolytic enzymes before transported though
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What does a cell wall do?
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Provides shape. barrier to env.
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What is a cell wall made of?
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peptidoglycan, a polysaccharide, linked by chemical bridges.
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Structure of cell wall
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two types of peptidoglycan: NAG is N-acetylglucosamine and NAM is N-acetylmuramic acid (NAM is only found in peptidoglycan). Linked to each other through beta 1,4 linkages.
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What are the four amino acids (tetrapeptide) attached to NAM?
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In gram -, L-alanine - D-glutaminate - Meso diaminopimelate and D-alanine. In gram +, L-lysine replaces diaminopimelate. Gram - = ala-glut-diaminopimelate-ala. Gram + = ala-glut-lys-ala
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What is the diff btw cell walls in gram + and -?
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Gram + have a pentaglycine bridge. 75% tetrapeptides are linked. 90% of cell wall is peptido. Gram - has 25% freq of linkage. 5-20% peptido
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Outer membrane
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only gram - have an outer membrane. phospholipid bilayer with LPS - lippolysaccharides that anchor to peptidoglycan layer and account for 40% of cell surface
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LPS components
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O-specific side chain. core polysaccharides (always the same), Lipid A portion
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O antigen
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polysaccharide that has 2,200 varients in Salmonella
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Lipid A portion
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glycophospholipid, toxic portion of gram - bacteria, responsible for fever and shock
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What are 3 ways bacteria will lack cell walls?
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1. mycoplasma 2. L forms - bacteria grown in presence of penicillin 3. Lysosyme hydrolyzes beta 1,4 bond destroying cell wall
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Periplasm
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(only in Gram -) the gap btw plasma membrane and outer membrane. Has many hydrolytic enzymes
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Capsules
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protects against phagocytosis. made of polysaccharide or glycoprotein.
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Pili
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Type 1 - attachment pili. Ex. Neisseria gonorrhoeae. F type - conjugatin pili
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What substances can only be found in bacteria?
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NAM and peptidoglycan
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What is a protoplast?
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Cell treated with lysozyme and sucrose so that it can be studied in a lab
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Run and Tumble
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Run - forward to food - flagella counterclockwise. Tumble - clockwise.
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Triclosan
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disinfectant. has high resistance among microbes
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Peptidoglycan Synthesis (simple)
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1. Building blocks gather in cytoplasm. 2. transfer through membrane to join existing cytoplasm
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Peptidoglycan Synthesis (descript)
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1. NAM and UDP = NAM-UDP + 5 aa. 2. attaches to bactoprenol-P to make NAM more hydrophobic for transport across membrane. 3. Complex is added to UDP-NAG by cross linking and through plasma membrane. 4. The new section adds by transglycosylation
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What are the 3 parts of flagella?
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Basal body, hook and filament
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One flagella is called ___. 2+ are called ____
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Monotrichous. Multitrichous
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Lophotrichous
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tuft of flagella
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Polar flagellated
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single flagellum at one or both ends of cell
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Peritrichous flagella
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throughout the cell surface
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Chemotaxis
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movement of bac away or towards chemical. use chemoreceptors (involves methylation and demethylation of certain proteins, MCP or transducers
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How many ribosomes are in a growing cell
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up to 30,000
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Gas vacuoles
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photosynthetic bac have these to maintain optimal depth for O2 and light by controlling buoyancy.
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Inclusion bodies
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reserves materials (lipids, polysaccharides and inorganic materials ) for bac in harsh env
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Inclusion bodies in cornyebacterium
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store polymetaphosphate. when stained with dye called Babes Ernst bodies.
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Inclusion bodies in Pseudomonas
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store hydroxybutyrate for C and E
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What bac make endospores?
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Bacillus and clostridium. formed in response to environmental stress
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What are endospores made of?
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made in bac out of calcium diplicolate
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Why make an endospore?
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bc they are highly refractile (resistant to heat and drying)
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What are the 5 stages of sporogenesis?
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1. Replicate Dna. 2. septum in membrane. 3. forspore developes. 4. forespore engulfed (now has a double membrane). 5. Coat is formed
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Cell wall - Who has it?
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Plants, algae and fungi
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Cell wall What is it for?
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maintain shape and rigidity, protection against osmotic stress
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What is the cell wall made of?
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Cellulose or chitin
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Sterols
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only in euks. make cell wall stronger in absence of cell wall
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Ribosome size in Euk and Prok
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Euk - 40S + 60S = 80S. Prok 30S + 50S = 70S
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vacuoles
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filled with fluid, usually seen in plant cells
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Lysosomes
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contain hydrolytic enzymes
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Euk cell movement
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Flagella, cilia, and cytoplasmic streaming
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Euk flagella
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consists of 9 pairs of microtubules, motion done by ATP
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Pseudopodia
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in Euks, movement like amoeba, involved in cytoplasmic streaming
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Chemotroghs
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energy obtained from the oxidation of chemical compounds (org or inorg)
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Autotrophs
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CO2 fixation
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What kinds of nitrogen do bac use?
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Nitrogen gas N2, nitrate NO3, and ammonia NH3.
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How do bac use nitrogen
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components in proteins, cell walls, nucleic acids etc
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psychrophiles
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-10C to 25C
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Mesophiles
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10 to 45C
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Thermophiles
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30 to 80C
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Extreme thermophiles
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greater then 80C
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Ways of measuring growth
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Counting chamber, Viable cells measured on agar plates, filtration (.22 or .45 um), turbidity, mass, growth changes and activity
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Counting chamber
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counts both live and dead. Need a large pop (10^6) to be valid
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Counting bac by mass
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industrial application, centrifuged paste, measure mass in kgs
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Metabolic Activity
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measure change in pH, O2, acid, and metabolic product
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Growth curves
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lag, exponential, stationary and death phases
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Sterilization
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killing or removal of all living organisms
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Autoclave
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121C for 15 minutes with 15 lbs/in2 pressure. Done by using flowing steam
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Tyndallization
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problem changes medium. 100C for 30 minutes for 3 days. 37C incubated for rest of time
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Pasteurization
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Two Methods. LTH Low tem hold - 62.8 for 30 min. HTST High temperature short term - 71.7C for 15 sec
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Pasteurization bac
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kills most bac but not all. destroys mycobacterium tuberculosis, brucella abortus, salmonella and lactococci
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Filtration
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.22 to .45 um. viruses will pass through
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Hepa filters
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99.97% of bacteria removed
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Method used to kill bac on tools (syringes and glassware)
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160-170C dry heat for 2-3 hours
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Ionizing radiation
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gamma rays, cobalt 60 is used for this method with various exposure times. used with food
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Nonionizing radiation
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UV radiation (260 nm) causes T-T dimers in DNA
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Antimicrobial
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chemicals that inhibit or destroy growth
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Cidal agents
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kill the bac
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static agents
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reversibly inhibit growth of organism. if agent is removed then org can grow
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lytic agents
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cidal agents that destroy microbes by lysis
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Disinfectants
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chemicals that destroy disease causing microbes and their products on INANIMATE
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Antiseptic
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less toxic then disinfectants. usually inhibit but do not always kill microbes
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Phenol coefficient
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measurement of germical action compared to phenol. choline is 10. means chlorine is 10 times more efficient then phenol
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Phenol
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since 1865 and lister, 5% solution kills bac and most spores by lysis
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Alcohols
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lipid solvents. 70% isopropanol
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Surfactants - soaps and detergents
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surface tension reducers - disrupt cell membrane
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Alkylating agents
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formaldehyde, glutaraldehyde, ethylene oxide. attach methyl or ethyl groups to proteins and DNA killing microbe
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heavy metals
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Mercury, silver, and copper. toxic bc they bind to sulfhydryl groups of proteins. copper sulfate is an algicide. silver nitrate is infant eyes
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Antibiotics
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waksman coined phrase. he discovered streptomycin
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Factors of a good Antibiotic
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selective toxicity. inhibit or kill microbe. Doesn't hurt host
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What are the modes of action of antimicrobials?
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WMPM. Inhibit wall. damage cell membrane. inhibit protein synthesis. inhibit metabolism.
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Penicillin
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inhibit transpeptidation step of peptidoglycan. ihibit cell wall
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Beta lactamases
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produed by resistant bac can hydrolyze penicillin. Semi synthetic penicillins are resistant
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Cephalosporins
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inhibit cell wall and are resistant to beta lactamases
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Antibiotics that damage membranes
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polymyxin. nystatin and amphotericin B
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Antibiotics that inhibit cell wall
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penicillin and cephalosporin
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Antibiotics that inhibit protein synthesis
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Tetracycline ,chloroamphenicol, erythromycin and Aminoglycosides (streptomycin, kanamycin and neomycin)
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Aminoglycosides
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streptomycin, kanamycin and neomycin. impair 30S ribosome function
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Tetracycline
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interfere with tRNA attachment to ribosome
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Chloroanphenicol
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binds to 23S RNA on the 50S unit inhibiting bond
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Erythromycin
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binds to 50S ribosome subunit to block peptide formation
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Structural analogs
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resemble cell metabolites and compete. Sulfonimides are similiar to PABA (precursor to folic acid) blocks vitamin synthesis
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What are the 2 kinds of Continuous culture?
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Chemostat and Tubidostat.
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Chemostat
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growth controlled by flow rate of sys (fresh nutrients)
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Turbidostat
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device measures turbidity and adds fresh nutrients
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Synchronous culture
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All pops grow in same phases or stage of growth. Get products at optimal rate
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What are the 3 types of work that bacteria do?
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Mechanical, Electrical and Chemical
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mechanical work
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movement of flagella, active transport of chemicals against a gradient
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Electrical
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movement in the gradient involves a charged chemical
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Chemical
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biosynthesis
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Chemical energy resides in the ______
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bonds of chemical molecules
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Exergonic
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gives energy. EXIT energy
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Endergonic
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needs energy
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What influences enzyme activity?
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pH, temp and ionic strength
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Pasteur effect
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when in air a facultative anaerbe will grow faster and form more CO2. BUT Co2 evolution and glucose utilization decrese bc glycolysis instead of fermentation
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What are the 3 types of work that bacteria do?
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Mechanical, Electrical and Chemical
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mechanical work
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movement of flagella, active transport of chemicals against a gradient
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Electrical
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movement in the gradient involves a charged chemical
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Chemical
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biosynthesis
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Chemical energy resides in the ______
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bonds of chemical molecules
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Exergonic
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gives energy. EXIT energy
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Endergonic
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needs energy
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What influences enzyme activity?
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pH, temp and ionic strength
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Pasteur effect
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when in air a facultative anaerbe will grow faster and form more CO2. BUT Co2 evolution and glucose utilization decrese bc glycolysis instead of fermentation
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