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62 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Requirements for microbial growth |
Temp pH Osmotic pressure Carbon Nitrogen,sulfur&phosphorus Trace elements Oxygen Organic growth factors |
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Classification of microbes by temperature |
Psychophiles Psychotrophs Mesophiles Thermophiles Hyperthermophiles |
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Cold loving microbes |
Psychophiles and psychotrophs |
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Human temperature loving microbes |
Mesophiles |
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Hot temperature loving microbes |
Thermophiles and Hyperthermophiles |
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Was is carbon needed for microbial growth? |
It’s the structural backbone of organic molecules |
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How is nitrogen aquiredwgats for microbial growth? |
Bacteria will decompose protein materials to steal nitrogen |
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What does it mean if bacteria only grows in the top of the test tube? |
It requires oxygen to grow. (Obligate aerobe) |
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What does it mean if bacteria only grows all over but primarily in the top of the test tube? |
It doesn’t need oxygen to grow, but it grows better with it. (Facultative anaerobes) |
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What does it mean if bacteria only grows in the bottom of the test tube? |
It prefers to grow with no oxygen (obligate anaerobes) |
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What does it mean if bacteria grows equally throughout the test tube? |
Oxygen has no effect on its growth. (Aerotolerant anaerobes) |
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What does it mean if bacteria only grows in the middle of the test tube? |
It grows best at the lowest amount of pressure (microaweophiles) |
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What is a culture medium? |
Nutrients prepared for microbial growth |
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Define inodefune culum |
Introduction of a microbe to a growth medium. |
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Define sepsis |
Bacterial comtamination |
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Define asepsisdefine steriliz |
Not sterile, but absent from significant contamination |
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Define sterilizationdefinutuon |
Removing and destroying all microbial growth |
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Define commercial sterilization |
Killing clostridium botulinum endoscopes from canned goods |
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Define disinfection |
Destroying harmful microorganisms |
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Define antisepsis |
Destroying harmful organisms from living tissues |
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Define sanitization |
Lowering microbial counts on eating utensils to safe levels |
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Define biocide (germicide) |
Treatments that kill microbes |
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Define bacteriostasis |
Inhibiting, not killing, microbes. |
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Effectiveness of tx to create microbial death depends on: |
1.# of microbes 2. Environment 3. Exposure/ contact time 4. Microbial characteristics |
Four things |
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How to control Microbial growth (3 ways) |
1. Alteration of membrane permeability 2. Damage to proteins 3. Damage to nucleic acid |
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How to control Microbial growth (3 ways) |
1. Alteration of membrane permeability 2. Damage to proteins 3. Damage to nucleic acid |
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Methods of microbial control: radiation |
Used ionizing, nonionizing and microwave radiation to damage the dna or bacteria |
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4 how Principles of good disinfectants |
1. pH 2. Organic matter 3. Concentration of disinfectant 4. Time |
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How to evaluate success of a disinfectant |
The use dilution test. |
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Types of Disinfectants: Phenolb |
(Carbolic acid) injures the lipids of the plasma membrane, causing leakage |
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Types of Disinfectants: bioguanides |
(Chlorahexadine) used in surgical hand scrubs to disrupt plasma membrane |
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Halogens |
(Chlorine and iodine) |
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Types of Disinfectants: alcohol |
*Can kill bacteria and fungi but not viruses and endospores. * destroy protein * optimum ethanol concentration is 70% |
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Types of Disinfectants: Heavy metals |
Include silver, mercury, copper, and zinc |
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Types of Disinfectants: Surface - Active Agents |
Not antiseptic but physically and mechanically moves microbes away through scrubbing. Ex: soaps and detergents |
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Types of Disinfectants: chemical food preservatives |
* sulfur dioxide * organic acid * nitrites and nitrates |
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What is DRT |
# of minutes needed to kill 90% of a microbial population at a certain temperature |
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Types of Disinfectants: antibiotics (bacteriocins) |
Proteins produced by one bacterium to kill another |
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Types of Disinfectants: Aldehydes |
Inactivates proteins by cross lining them with functional groups. Ex: gluteraldehyde, one of the few liquid sterilizing agents |
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Types of Disinfectants: chemical sterilization |
Not practical |
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Types of Disinfectants: supercritical fluids |
Combines physical and chemical methods. Example: CO2 with both gaseous and liquid properties
Usually used for medical implants |
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Types of Disinfectants: Peroxygens |
Oxidizing agents that include hydrogen peroxide |
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Define genetics |
The science of heredity, how genes work, and how they carry and express information |
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What controls gene expression? |
Operons |
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The alteration of bacterial genes and of gene expression can:what carries genes |
Cause disease Prevent disease Or can be manipulated for human benefit |
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What carries genes?what |
Chromosomes |
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What are genes?define |
Segments of DNA that create a product, usually protein |
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Methods of microbial control: Moist heat sterilization (boiling) |
* steam must contact the items surface * done in an autoclave (steam under pressure) *need to exhaust (remove steam) and allow to cool prior to removing |
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Define genome |
All info in a cell |
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What’s a genotype? |
The genetic makeup of an organism |
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What’s a phenotype?what |
The expression of the genes |
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What must you have for dna replication? |
ATP |
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Define mutation |
A permanent change in the base sequence of DNA (good or bad) |
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Define mutagen |
Agents that cause mutations |
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Define spontaneous mutations |
Occur without a mutagen |
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Methods of microbial control: Pasteurization |
It’s thermoduric, meaning organisms do survive, which is why milk eventually curdles |
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Methods of microbial control: Dry heat sterilization |
Cooking on a hot open flame or incineration such as an oven |
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Methods of microbial control: Filtration |
A screen like material used for heat sensitive items.
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HEPA |
High-efficiency particulate air filter. Used for removing microbes |
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Methods of microbial control: low temp |
Refrigeration, deep freezing or freeze drying to slow growth |
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Methods of microbial control:osmotic pressure |
Uses salts and sugars to create a hypertonic environment, which causers water to leave the cells |
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Methods of microbial control: Desiccation |
Absence of water to prevent metabolism |
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