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Explain these ways to measure growth ?
spread plate method,
pour plate method–
Colony counter–
Cell Counts–
Petroff-Hausser counter
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How do you use this formula ?
Nt=N02n
The doubling time is 20 minutes at 37 oC. The bacteria have been incubating for 8 hours, which means there will be doubling taking place 3 times an hour. So there will be (8 hrs x 3) = 24 doubling moments taking place.There will be 24 generations of bacteria after 8 hours.
- 5000 x 224 = Nt
- Nt = 83,886,080,000
- or 8.388 x1010
Utilizing the equation N t=N o x 2 n
- Nt=population size at specified time
- No= initial population size
- n= # of generations
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What is an
Aerobe:
Obligate aerobe:
Microaerophile:
Aerobe: organism that grows in the presence of oxygen
Obligate aerobe: requires atmospheric oxygen (20% O2) for growth and metabolism
Microaerophile :requires O2 for metabolism, but at very low concentrations
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What is an
Anaerobe :
Obligate anaerobe:
Facultative anaerobe:
Aerotolerant:
Anaerobe: organism that grows in the absence of oxygen
Obligate anaerobe:cannot grow in the presence of oxygen
Facultative anaerobe: able to use both pathways; therefore, does not require O2 , but grows better in its presence–
Aerotolerant: does not require O2 but can withstand the presence of O2; grows just as well in and out of the presence of O2
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Where do each of these grow in a test tube culture ?
Obligate aerobe
Facultative anaerobe
Obligate anaerobe
Microaerophile
Aerotolerant
Obligate aerobe : Top growth
Facultative anaerobe: Full column
Obligate anaerobe: bottom growth
Microaerophile : Middle growth
Aerotolerant : Full column
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What are the important enzymes that destroy free radicals ?
- Catalase:
- Peroxidase:
- Superoxide Dismutase:
- Superoxide dismutase & catalase:
- Superoxide reductase:
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What are Cytochromes and Siderophores ?
–Cytochromes: proteins involved in electron transport and redox reactions
-Siderophores: organic molecules that bind to Fe3+ making it possible for the cell to take up iron
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What is the purpose Hydroxamic acid and Enterbactins in the function of bacteria ?
Hydroxamic acid: strongly chelates iron–
Enterobactins: produced by enteric bacteria like E. coli and Salmonella
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How do the two different photosynthesis differ ?
Differ in the wavelengths at which light is absorbed
Cyclic photophosphorylation–the electrons return to the chlorophyll after passing through the electron transport chain
Non-cyclic photophosphorylation–the electrons are used to reduce NADP and electrons are returned to chlorophyll from H2O and H2S
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In terms of Oxygenic vs. Anoxygenic photosynthesis ,Which is for (Chlorophyll or bacteriochlorophyll) ?
Which one has water as the electron donor ?Which one produces oxygen?
Which one is frequently and aerobic process?
- Oxygenic = Chlorophyll
- Anoxygenic=Bacteriochlorophyll
- Oxygenic = water as electron donor
- Oxyegnic= produces oxygen
- Oxygenic = frequently aerobic
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What does a porphyrin do in chlorophyll ?
What colors does it absorb and transmit?
- It binds to Mg2+
- Absorbs light red and blue light; transmits green light
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What are the absorption spectrums for Chlorophyl a and Chlorophyl b?
Which is the most common ?
Which one does alage use ?
680nm and 660nm
680nm is the most common
680nm
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Where are thykaloid cells located in Eukaryotes and Prokaryotes ?
Eucaroytes: Occurs in thykaloid membranes within the chloroplast•Procaryotes: Occurs in thykaloid membranes within the cell
Eucaroytes: Occurs in thykaloid membranes within the chloroplast
Procaryotes: Occurs in thykaloid membranes within the cell
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what is the final electron acceptor in a bacteriochlorophyll ?
Sulphur
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What type of bacteria use bacteriochlorophyll ?
Blue and Green bacteria
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Where is the bacteriochlorophyll located in the following bacteria.
Purple bacteria:
Heliobacteria:
Green bacteria:
Purple bacteria: invagination of the cytoplasmic membrane–
Heliobacteria: cytoplasmic membrane (unique)–
Green bacteria: both cytoplasmic membrane and membrane-enclosed structures called chlorosomes
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what are carotenoids ?
- -Most widespread; associated with chlorophyll or bacteriochlorophyll
- –Hydrophobic pigments firmly embedded in the membrane
- –Oxygenic photosynthesis: Typically yellow, green, red, brown
–Anoxygenic photosynthesis: Typically red, purple, pink, green, yellow, brown
–Do not function in ATP synthesis
–Transfer light to the reaction centers•Reaction centers are a complex of pigments used to harvest light and generate ATP
–Act as photoprotective agents from toxic oxygen species (e.g. singlet oxygen)
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What are Phycolbilins / Phycobiliproteins ?
What bacteria usually has them ?
Phycobilins/Phycobiliproteins–Present in cyanobacteria and red algal chloroplast
–Red (phycoerythrin) or blue (phycocyanin) pigments
–Allophycocyanin (red pigment)•Occur in aggregates called phycobilisomes, attached to the photosynthetic membranes
Usually seen in serratia
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What are osmotolerant microbes ?
What are Halophiles?
•Osmotolerant: to grow over a wide range of water activity or osmotic concentration.
•Halophile:require high levels of NaCl to grow; usually above 0.2M
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What are Acidophiles , Neutrophiles , and Alkalophile ?
what type are usually found in our bodies ?
Where would the bacteria Helicobacter pylori be?
- Acidophile: pH 0 and pH 5.5
- Neutrophile: pH 5.5 and pH 8.0
- Alkalophile: pH 8.5 and pH 11.5
Neutrophiles are usually in our bodies
Helicobacter pylori would be an acidophile
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What is a
Psychrophile
Psychrophile
Psychrotroph
Mesophile
Thermophile
Hyperthermophile
Which tend to live in the human body ?
- Psychrophile– 0-15oC
- Psychrotroph– 20-30oC; minimum range:
- 0-7oC; maximum: 35oC.
- Mesophile–o20-45oC
- Thermophile–55-65oC
- Hyperthermophile (extreme thermophile):80-113oC
Mesophiles
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What is the difference between Barotolerant and Barophile ?
Barotolerant–able to grow at different ranges of hydrostatic pressures
Barophile–Grows more rapidly at high hydrostatic pressures
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