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Which type of bacteria can make spores?
Only certain gram+ bacilli
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How do spores look after gram staining?
Spores do not gram stain so they show as clear.
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Why do spores not gram stain?
Bc there are no cell walls associated with bacterial spores.
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What has to happen before bacteria will for
a spore?
It must feel threatened by hostile conditions
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Name 6 hostile conditions bacteria may face:
- - extreme changes in temp
- - change in pH
- - dry conditions
- - antibiotics
- - O2 levels
- - lack of nutrients/food
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How many spores can 1 bacilli make?
Only one.
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How long does it take spores to develop?
Some 6-8 min; 10 min; 30+ minutes.
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What is a vegatative cell?
A cell that can not or is not making a spore. Cocci and spiral are always vegatative.
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What is a sporulating cell?
A cell making a spore. Gram+ bacilli making a spore.
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Name 5 types of sporulating bacteria
Anthrax, C. diff, tetanus, botulism, gas gangrene
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Name 5 things that can kill a spore
- - intense heat (1300 F +)
- - autoclaving
- - hibiclens (chemical)
- - cidex
- - tetanus vaccine
- - lab table disinfectant
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What does not kill spores?
Alcohol, hydrogen peroxide; mild radiation, sunlight, household cleaners
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What is a solute?
Something that will be dissolved
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What is a solvent?
Disolves the solute (water)
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Def hypertonic:
When the solution has a higher concentration of solute and a lower concentration of solvent
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Def osmosis:
The movement of water molecules from an area of low solute concentration to an area of high solute concentration
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If you place a bacteria in a hypertonic solution what will happen?
Water will move out of the bacteria causing it to shrivel and die.
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What are the four steps to gram staining?
- 1. Flood with crystal violet (primary stain)
- 2. Flood with iodine (mordant)
- 3. Use decolorizer (95% alcohol)
- 4. Flood with safranin (counter stain)
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List 5 characteristics of gram+ cell walls
- - thick peptidoglycan layer
- - tightly bonded polysaccharides
- - cell wall and cell membrane close together
- - holds in purple from crystal violet
- - no porins
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List 5 char of gram- cell walls
- - thin peptidoglycan layer
- - loosely bonded polysaccharides
- - cell wall and cell membrane further apart
- - stains pinkish red from safranin
- - contains porins (integral proteins with a pore)
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Name the 4 types of flagellum
- - monotrichous: one flagella
- - lophotrichous: group or cluster of flagella found at one end
- - amphitrichous: onr flagella at ea end
- - peritrichous: completly covered in flagella
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Name two bacterial movements in responses to stimuli and describe
Phototaxis: movmnt by light
Chemotaxis: movmnt by chemicals
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What are fimbriae used for?
They monitor changes in stimuli; similar to a nervous system
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What are pili and how are they used?
A reproductive structure used to transfer genetic material
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What organelles are NOT found in bacterial cells?
Nucleus, nuclear envelope, rough ER, smooth ER, golgi apparatus, lysosomes and mitochondria
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Name 9 ways bacteria can be classified
- 1. Shape
- 2. Oxygen needs
- 3. Movement
- 4. Gram staining (+ -)
- 5. Cell wall thickness
- 6. Ability to form a capsule
- 7. Ability to make a spore
- 8. Type of hemolysis
- 9. Ability to release a toxin
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Who is the father of modern microbiology and what were some of his contributions?
Rabies vaccine, germ theory, disproved abiogenesis
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Name 5 things that can be learned from the Genus of a species?
- Discoverers name
- Disease name
- Place of discovery
- Shape or clustering
- Color pigment on blood agar
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Name 8 reasons bacteria are important to our lives.
- 1. Can make oxygen
- 2. Keeps immune system in balance
- 3. Can decompose and recycle nutrients
- 4. Beginning of the food chain
- 5. Make vitamins in our colon
- 6. Used to make food
- 7. Make drugs
- 8. Make sulfur and nitrogen for plants
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How is bacteria measured?
In microns
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How big is a micron?
It equals 1/25 of 400ths of an inch
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What are the four stages of the bacterial growth curve?
Lag, growth, stationary, death
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What happens during the lag phase?
Bact adapt to growth conditions
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What happens during the growth phase?
Exponential growth in population
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What happens during the stationary phase?
Growth rate slows due to nutrient depletion, decreased O2, and accumulation of toxins
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What happens during the death phase?
Bact run out of nutrients and die.
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Define saprophyte
Organism that feeds on something dead
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Define parasite
An organism that feeds on something living and harms it. (all pathogenic bacteria)
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Define faculatative saprophyte
This bacteria prefers to feed on something living but can feed on something dead
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Define aerobic
Can live in the presence of free atmo O2
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Define anerobic
Can live in the absence of free atmo O2
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Define Obligate anerobe
Must live in absence of free O2
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How is bacteria effected by drying?
Can kill it
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What are the four steps in binary fission?
- 1. DNA replication
- 2. Chromosome segregation
- 3. Cytokinesis
- 4. Septum completion, daughter cells are formed
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Define binary fission.
A process in which a cell grows twice its normal size and divides in half to produce two daughter cells of equal size.
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What is snapping and how does it vary from binary fission?
- Variation of binary fission that differs by:
- A) only the inner portion of the cell wall is deposited across the dividing cell
- B) tension develops and the daughter cell is attached by a hinge
- C) the daughter cell may sepArate from its original attachment site.
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What is budding?
An outgrowth of the original cell ( bud) receives a copy of the genetic material and enlarges. The bud separates from the parent cell. The parent will continue to make additional buds.
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What is conjugation?
The transfer of genetic material through the conjuction pili.
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Where are the genes for conjugation found?
On the plasmids (F+). F- cells lack conjugation genes and also lack pili.
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What is the most common bact to undergo conjugation?
E. coli; conjugation can occur btwn two diff species. Bacterium and yeast or bacterium and plant.
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What is the process of bact conjugation?
- 1. Donor cell attaches to recipient cell with its pilus. The pilus pulls the cells together.
- 2. The cells contact one another
- 3. One strand of plasmid dna transfers to the recipient.
- 4. The recipjent becomes an F+ cell.
- 5. The donor replaces its donation Section of dna.
- 6. The new F+ cell is ready to live a full productive life.
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Define synergism.
Two diff bact species living together; one enhances the growth of the other.
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Antagonism is:
Two diff bact ljving together; one inhibits the other.
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What effect does the following have on bact:
- heat
- cold
- acididty
- electricity
- radiation
- high salt/sugar
- - heat will kill or slow down
- - cold will kill or slow down
- - acididty: bact love pH of 6-8 if very acidic or basic will die
- - electricity does nothing
- - radiation can kill at very high doses
- - high salt/sugar can make a hypertonic enviro and cause the bact to shrivel and die
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What is bacterial hemolysis?
Red blood cell destruction
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