Term
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Definition
| temperature at which maximum enzyme activity occurs |
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Definition
| cells will begin to denature and and loose activity |
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Definition
| chemical activity slows down and some denaturization will occur |
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Term
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Definition
| transport of nutrients into the cell also decreases due to fluidity changes in the membrane |
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Definition
| membrane lipids can be destroyed resulting in serious damage to the membrane and death of the organism |
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Definition
| optimal growth between 20c and 50c (most bacteria fall into this class) |
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Term
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Definition
| optimal grpwth between -5c and 20c (found in supercold waters of antartic and artic) |
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Definition
| optimal growth between 50c and 80c (found in soil) |
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Term
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Definition
| growth optimum above 80c (found near volcanic heated hot springs and thermal vents deep w/in the ocean floor) |
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Term
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Definition
| some bacteria w/in classes are capable of growth at temp. lower or higher than their optima. For example, some mesophilic bacteria can grow at 4c (refrig temps) and cause food spoilage. |
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Term
| the equation for Ph of a solution: |
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Definition
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Term
| what range do most bacteria grow over? |
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Definition
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Term
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Definition
| a medium where solute concentration on the outside of the cell are lower than than the cytoplasm (the rigid cell wall protects the membrane from being damaged by osmotic pressure against it) When the pressur becomes to great it will burst |
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Term
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Definition
| solute concentration is greater on the outside of the cell relative to the cytonplasm (this causes water to diffuse out of the cytoplasm and results in dehydration or plasmolysis) |
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Term
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Definition
| solute concentration is the same inside and outside the cell |
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Term
| What is the water activity? |
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Definition
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Term
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Definition
| require high concentrations of sodium chloride (salt) to grow |
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Term
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Definition
| able to grow in environments where sugar concentrations are excessive |
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Term
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Definition
| capable of growth in moderate concentrations of salt |
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Term
| What is the wavelength range of ultraviolent light? |
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Definition
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Term
| What is the most germicidal wavelength? |
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Definition
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Term
How does UV light kill bacteria?
What are pyrimidine dimers? |
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Definition
| It kills the bacteria by mutating it. The pyrimidine dimers form when a covalent bond is formed between to adjacent thymine or cytsine molecules in a DNA strand. Dimers essentially cause the DAN molecule to become deformed so that the DNA polymerase cannot replicate DNA strands past the site of dimer formation, nor can genes past this point be transcribed. |
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Term
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Definition
| It enzymatically removes the dimers and inserts in their place new pyrimidine molecules. Unlike DNA polymerase, enzymes of the SOS system can move beyond the point where dimers occur in the molecule (If UV exposure is too great the SOS system is unable to cope and this results in the cell death) |
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Term
| What is resistant to UV light? |
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Definition
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Term
| What type of bacteria are more resistant than other forms of bacteria to UV light? |
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Definition
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Term
| what is the most widely used skin disenfectant? |
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Definition
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Term
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Definition
| chemotherapeutic agents of low molecular weight produced by microorganisms that inhibit or kill other microorganisms |
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Term
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Definition
| Antimicrobic agents that are man-made |
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Term
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Definition
a standardized system that takes all variables into consideration
1)Entire surface of a plate of nutrient medium is swabbed w/ organism to be tested
2)Handle of dispenser is pushed down to place 12 disks on the medium. In addition to dispensing disks, this dispenser also tamps disks onto medium
3)Cartridges can be used to dispense individual disks
4)After 18 hours of incubation, the zones of inhibition are measured in milimeters. Significance of zones is determined from Kirby-Bauer chart |
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Term
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Definition
Meida that permits the growth of certain organisms and prevents or inhibits the growth of others
(examples:sodium chloride agar(staphylococci), Mitas, EMB, MacConkey,and Bile) |
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Term
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Definition
Media that incorporates ingredients that cause certain organisms to develop different appearance from other microbes growing on the same medium
Examples:Mitis, Blood, EMB, MacConkey, Bile |
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Term
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Definition
| A differential media that allows you to determine if a bacterial colony has produced the enzyme hemolysin and whether the resulting hemolysis is partial(alpha) or complete(beta). If no change is present it is gamma hemolysis. Hemolysis is significant only for gram + cocci. |
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Term
| EMB (Eosin Methylene Blue) |
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Definition
| A selective and differential media that is selective for Gram - organisms b/c of a bacteriostatic(not bactericidal) effect of the dye, and causes the colonies to appear purple or dark-centered w/ colorless edges. Colonies of genus Escherichia have metalic appearance called green sheen. Colonies of organisms unable to ferment lactose appear colorless. It differentiates btwn lactose and non-lactose fermenting bacteria |
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Term
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Definition
| Both selective and differential, Agar that contains bile salts and a small amout of crystal violet. Both of these will inhibit the growth of gram+ bacteria. It also contains lactose and neutral red pH indicator, which colors lactose-fermenting colonies red and may result in the formation of a red precipitate in the medium surronding the growth. Non fermenters-colorless. Also inhibits the swarming effect of Proteus |
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Term
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Definition
| Contains mannitol, 7.5% NaCl, and phenol red indicator. The NaCl inhibits organisms other than Staphylococci. If fermented to produce acid, the phenol red in the medium changes color from red to yellow |
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Term
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Definition
| A selective and differential medium most selective for streptococci containing crystal violet and inhibits the growth of most gram- bacilli and most gram+ bacteria |
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Term
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Definition
| A selective and differential media that bests help to identify group D streptococi. Both enterocoocal and nonenterococcal species of group D are able to hydrolyze esculin the slant causing it to blacken (positive result) |
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Term
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Definition
| A medium that is selective for gram +, staphylococcus bacteria which are almost always coagulase positive. Coagulations is anything from a singl-loose clot to a solid immovable clot |
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Term
Diseases this organism causes:
boils, carbuncles, impetigo, meningitis, osteomyelitis, urinary tract infections, toxic shock syndrome, and food poisoning |
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Definition
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Term
Diseases this organism causes:
scarlet fever, rheumatic fever, septic sore throat, erysipelas, puerperal fever, bronchial pneumonia, meningitis, and wound infections |
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Definition
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Term
| Description of Staphylococus |
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Definition
| Gram-positive spherical cells that occur singly,(sometimes in pairs) and most frequently in irregular clumps (grape-like cluster). Also is coagulase positive |
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Term
| Description of Streptococci |
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Definition
| Gram-positive cocci normally occurring in short or long chains. Do not form catalase. Usually require enriched media to grow (blood agar) |
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Term
| Description of pyogenic Streptococcus |
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Definition
| Beta-hemolysin damages human tissues causing an influx of white cells to the site of injury. These organisms are pus-forming streptococci |
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