Term
Phosphotransferase system
(PTS system) |
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Definition
| Type of Active transport that uses ATP and chemically modifies the material as it enters the cell |
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Term
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Definition
| An organism which successfully replicates to form a colony |
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Term
Absolutely - these are called "dormant"
They're called
Viable-but-not-cultureable (VBNC) |
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Definition
| Could a cell be alive but not replicate to form a colony? |
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Term
False
some things grow from clusters and not just one single cell |
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Definition
| All cells in colony derive from single cell. T/F? |
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Term
Dilution streaking
-'streak plate' dilutes cells from
many in 1st quadrant to only
several in the fourth
Dilution in liquid culture
- reduces number of cells in each
tube |
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Definition
| Two strategies for obtaining pure cultures? |
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Term
- Total Counts/ Direct Count
- Spectrophotometer/Turbidity
measurements
- Viable counts |
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Definition
| Methods for counting bacteria? |
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Term
Petroff-Hauser counting chamber
(type of hemocytometer) |
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Definition
Type of total count/Direct count:
• viewed under microscope & cells in
grids are counted
• Counts cells directly |
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Term
| Coulter Counter or fluorescence activated cell sorter (FACS) |
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Definition
Type of total count/Direct count:
cells can be counted electronically using ? |
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Term
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Definition
| In which total count/direct count method do you count live cells? |
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Term
| Spectrophotometer/Turbidity measurements |
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Definition
• Measures optical density
• indirect but rapid
• a suspension of cells looks Turbid (cloudy); cells scatter light passing through suspension
• more cells, more turbid, more light is scattered
• can’t tell if cells are alive or dead
• For turbidity measurements to be substituted for direct counting methods a standard curve must be made
• Once a standard curve is made for a specific organism growing in a specific culture medium, it can be used for future cultures of the same organism in the same medium to estimate cell numbers. |
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Term
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Definition
| Do not have to dilute sample before spread plates or pour plates can be made. T/F? |
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Term
Generation time
(aka doubling time) |
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Definition
| amount of time it takes for one cell to turn into two |
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Term
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Definition
| in ideal conditions how long does it take for 1 cell of E. coli to generate? |
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Term
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Definition
| characteristic type of growth pattern of microbial populations where the number of cells doubles over a regular time interval. |
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Term
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Definition
| graph of number of cells Vs time |
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Term
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Definition
| When does the adjustement period occur? |
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Term
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Definition
| During which phase do we want to do tests on culture? |
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Term
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Definition
| What stage will cells begin to create endospores if capable of doing so? |
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Term
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Definition
•Key nutrient will run out or toxic waste product will build up
•Most cells survive but stop dividing but not replicating
•Some cells form spores (endospores), some become smaller |
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Term
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Definition
| If you take sample out of this phase and put into a new plate they will have a much longer lag time* |
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Term
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Definition
| Constant volume of culture medium; closed system – nothing added or removed; commonly used in lab |
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Term
| Nutrient medium continually altered by metabolic activities of organisms growing in it; nutrients depleted; wastes build up |
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Definition
| What happens to medium when organisms are growing in it? How does it change over time? |
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Term
Continuous Culture
Our digestive system is a continuous culture |
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Definition
Fresh medium constantly added, used medium constantly removed, nutrient concentration stays the same.
What is an example of this? |
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Term
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Definition
| continuous culture device – allows cell populations to remain in exponential growth for long periods |
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Term
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Definition
| what are two bacteria that create disease by use of endospores? |
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Term
some species of Gram Positive
rod-shaped bacteria |
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Definition
| What two types of bacteria utilize endospores as a dormant survival structure formed during harsh conditions? |
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Term
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Definition
| With enough heat or radiation it is possible to kill endospores. T/F? |
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Term
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Definition
formation of an endospore when environmental conditions
are not favorable. Takes about 8 hours in B. subtilis. |
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Term
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Definition
| formation of a vegetative cell from an endospore when conditions are favorable |
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Term
Core
Cortex
Spore-Coat
Exosporium |
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Definition
- center of endospore. Contains cell
wall, CM, cytoplasm & nucleoid
- Purpose is to protect the nucleoid
surrounds core. Made of loosely
cross-linked peptidoglycan.
- protein which covers cortex.
- thin layer of protein which covers
the spore coat |
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Term
| Calcium-diplicolinic acid |
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Definition
| helps dehydrate endospore, stabilizes DNA & protects it from heat denaturazation |
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Term
| Small acid-soluble proteins |
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Definition
| Protect DNA from UV radiation, desication, dry heat and also serve as carbon and enerygy source during germenation |
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Term
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Definition
Cell differentiation:
Found in some species of autotrophic cyanobacteria such as anabanea |
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Term
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Definition
| Heterocytes fix nitroget. Every ___ cell creates a heterocyst. |
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Term
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Definition
| These form inside fruiting body and are then released into surroundings to find new nutrients |
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Term
Myxococcus xanthus
-form myxospores |
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Definition
| Some species such as _____________________ for a mound called a fruiting body in response to starvation. (Myxospores) |
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Term
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Definition
| actinomycetes form spores and are relesed into surrounds to find new nutrents. What are they called that are being released? |
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Term
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Definition
• Look like fungi
• In response to starvation, produce arial hyphae with spores just like fungi |
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