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40 Cards in this Set
- Front
- Back
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3 physical factors required for microbial growth. |
Temperature, pH, osmotic pressure |
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Psychrophiles |
-10-20°C |
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Mesophiles |
10-50°C |
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Thermophiles |
40-70°C |
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What is the optimal pH range for bacteria? |
6.5-7.5 |
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What is the optimal pH range for fungi like molds and yeast, which can also be human pathogens? |
5-6 |
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Osmotic pressure |
The force caused by a solvent when it is moving form an area of high concentration to an area of low concentration. |
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Hypertonic |
Having a higher level of concentration. |
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Isotonic |
Having the same level of concentration. |
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Hypotonic |
Having a low level of concentration. |
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If a bacteria was placed in a hypertonic solution, would water enter, leave, or leave equally in the cell? |
Water would leave the cell. |
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If a bacteria was placed in a hypotonic solution would water enter, leave or leave equally in the cell? |
Water would enter the cell. |
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Would bacteria swell in a hypotonic, hypertonic, or isotonic solution? |
Hypotonic solution |
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Trace elments |
Iron, copper, molybdenum and zinc in small amounts that are used ad enzyme cofactors. |
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What molecule in the cell or body requires carbon? |
Glucose and triglycerides. |
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What molecule in the cell or body requires nitrogen? |
Proteins. |
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What molecule in the cell or body requires sulfur? |
Amino acids and vitamins. |
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What molecule in the cell or body requires phosphorus? |
Nucleic acids |
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For what cellular process is oxygen required by many organisms? |
Aerobic cell respiration |
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Biofilm |
A bacterial community that forms a slime layer. |
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Why do pathogens find it advantageous to form biofilms? |
Because it shelters them from drying out, immune systems and antibiotics. |
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Culture media |
nutrients prepared for microbial growth. |
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Sterile |
without living microbes |
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Inoculums |
Introduction of microbes to the medium |
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Culture |
The microbes growing in the medium |
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Agar |
Complex polysaccharide that is used in Petri dishes, slants, and deeps. |
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Chemically defined media |
A medium where the exact chemical composition is known. |
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Complex media |
Medium composed of extracts and digests of yeast, meat, or plants. |
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Reducing media |
Medium, used to grow anaerobic cultures, that is heated to drive off O2. |
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Capnophiles |
Microbes that require high levels of CO2 concentration. |
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Biosafety Level 1 |
No safety precautions |
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Biosafety Level 2: |
Lab coat, gloves, eye protection. |
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Biosafety Level 3 |
Biosafety cabinets for airborne transmission prevention. |
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Colony |
A population of cells formed from a single cell or spore or from another group of attached cells. |
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What is the purpose of the streak plate method? |
It purifies or separates different species of microbes into different colonies. |
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Where would you keep a bacterial culture you wanted to keep using for a few days? |
A refrigerator |
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How would you preserve a sample of bacteria for months to several years? |
Lyophilization |
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How and why are organisms preserved in lyophilization? |
They are frozen and dehydrated by a vacuum. |
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Name 3 ways to culture anaerobic bacteria? |
Reducing media, brewer anaerobic jar, anaerobic chamber. |
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In reducing media, what chemical is used to bind oxygen? |
Thiglycolate |
