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74 Cards in this Set
- Front
- Back
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Archaea are divided into __ groups.
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5 physiologically distinct.
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What is in the phylum crenarchaeota?
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mesophlic,thermophilic, and hypothermophilic. The main oceanic archael species is the mesophiles.
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What is in the phylum euryarchaeota?
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diverse groups containing methanogens, extreme halophiles, and sulfur metabolizers.
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Methanogenesis is..
Produced by... |
the production of methane. The organisms only found in the euryarchaeota.
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What is required for methanogenesis to occur?
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H2 + CO2 or formate (sometimes others), anaerobic conditions
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In methanogenesis, ATP production is controlled by..
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PMF generation, but the details are unclear.
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Where are methanogens found?
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marine sediments, swamps, protozoa, and rumens of cows.
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One cow can produce ____ of methane a day.
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200-400 liters
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Methane is a potent....
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greenhouse gas, but a clean burning fuel.
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Halobacteria are absolutely dependent on..
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high salt (best growth at 3-4 M).
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What are some of the features of H. salinarium?
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Purple membrane composed of bacteriorhodopsin (light driven proton pump), halorhodopsin (light driven transporter) and 2 sensory rhodopsins that control movement in response to red & blue light.
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Bacteria are divided into ____ phyla in Bergey's. How many are Gram -/+?
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24; - = 22; + = 2
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DNA analyses suggest at least ___ phyla.
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40
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What is the classification for Bergey's according to?
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the SSU 16/18 rRNA sequences, GC content, metabolism, habitat, and phenotype.
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The phylum Deinococcus-Thermus stains ___ but has aspects of ____ like...
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Gram +; Gram -; outer membrane, ornithine (which is neither + or -) in place of lysine in the peptides that get cross-linked, and they lack techoic acid.
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D. radiodurans is resistant to....
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extreme dessication and high levels of radiation )both produce DS-DNA breaks).
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What is a reason for D. radiodurans being resistant to so many things?
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Because they are in a tetrad shape. Nucleoids also help.
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What do the Nucleoids do?
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They are in the different parts of the tetrad and they fuse to provide template for fixing DS-DNA breaks.
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What is the habitat for D. radiodurans?
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It is found in many so it is unknown.
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There are ___ phyla amongst the Gram -, in the photosynthetic bacteria that are classified how?
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by types of Chl/Bchl/accessory pigments and reductants used.
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The Gram + species in the photosynthetic bacteria are called...
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heliobacteria. (phylum firmicutes).
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In photosyntehtic bacteria, which groups use inorganic materials and which use organic for electrons?
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Green sulfur and purple sulfur use inorganic and Green nonsulfur and Purple nonsulfur use organic sources.
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Five photosythetic phyla have all...
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passed around genes for photosynthesis, 50 of them found common to all of them.
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All non-oxygenic phyla use sulfur and organic molecules for what?
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To provide reducing power to make NAD(P)H
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Different organisms use pigments that.....
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absorb light at different wavelengths
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Cyanobacteria are ____ life forms responsible for ______.
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very old; levels of O2 in the air.
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What happened to ancestors of cyanobacteria?
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they were captured by early eukaryotic cells to become chloroplasts.
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How many photosystems does cyanobacteria use, and what do they use?
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2; H2O as an electron donor, O2 as a product.
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Cyanobacteria contains what types of chlorophyll?
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Chl a and Chl b.
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What is the name for containing both chl a and chl b?
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prochlorophytes
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What is special about the genus of cyanobacteria Anabaena?
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They have cells that can differentiate for different functions.
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What is an akinete?
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It is a type of cell differentiated by anabaena that are thick-walled dormant cells that survive dessication.
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What are heterocysts?
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It is a type of cell differentiated by anabaena that differentiate when N sources are limited. N fixing only occurs in anaerobic cells, however heterocysts have thick walls that don't let in atmosphereic O2, they only use Photsystem I (no O2 production, makes PMF for ATP) and fix N2 for neighboring cells. Glutamine can go out the wall, and carbohydrates can come in.
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Chlamydia has...
It also lives and grows... |
1. no cell wall, obligatory intracellular parasite (.2-1 micrometers).
2. Inside our cells. |
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Two forms of chlamydia.
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EB (elementary body) form and RB form.
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The EB form of chlamydia form has....
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a highly cross linked outer membrane. Its function is to survive extracellularly. It is metabolically inactive, but it has structures on its surface to make it infective.
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How does the EB for of chlamydia bind?
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It binds to mucosal cells and are endocytosed. It then converts into a metabolically active form called the reticulate body.
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Which form of chlamydia is not infective?
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RB. They can divide and divide, but they are not infective.
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The reticulate bodies have to ____ before lysing the host cells.
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reconvert to EBs
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What is the most prevelant of the chlamydia pathogens?
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C trachomatis. It is the greatest cause of blindness in the world.
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How is chlamydia spread?
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Some are spread sexually, some are spread through inanimate objects. The infected person gets it in their eye and can get blindness. It infects the mucosal cells.
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It is estimated that _______ infections occur per year worldwide.
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500 million
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What else can C trachomatis cause?
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Conjunctivitis (leads to blindness), PID (Pelvic inflammatory disease) + other diseases.
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Spirochetes that cause Lyme disease are all from the genus....
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Borrelia (B. burgdorferi)
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How is Lyme Disease spread?
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From tick bites that were on deer or field mice. They then bite humans.
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What are the stages of Lyme Disease?
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1st stage: flu-like symptoms + rash
2nd stage: multi-organ inflammation 3rd stage: Alzheimers/MS type of illness. |
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__ large classes in phylum Proteobacteria, all related by SSU analysis.
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5; α β γ δ ε
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Proteobacteria are all...
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Gram negative.
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Membres of the Proteobacteria phylum have...
They are thought to have been derived initially from.... |
a very diversematabolism; the purple bacteria.
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What is Agrobacterium tumefaciens used for?
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genetically engineer plants
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Agrobacterium tumefaciens contains a....
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special Ti (tumor inducing) plasmid that can be genetically engineered in E. coli, then transferred bacl to the Agrobacteria via conjugation.
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How is the DNA transfered from the Agrobacteria to the plant cell?
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The T DNA is transferred via conjugation.
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What happens if the agrobacteria doesn't bind to the plant cell?
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Use normal wound response. It can also be placed in there by a particle gun.
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How can agrobacteria be used?
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Genetically engineering plants: herbicide resistance, Bt crops (bugs eat the plants, they die), ethylene resistance (delayed ripening by inputting mutant receptors).
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What is Caulobacter crescentus known for?
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Because of it's many developmental stages. They always take place at the same time.
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Explain the cycle for Caulobacter crescentus.
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You have a cell with a flagella called a swarmer cell. It loses it flagella and grows a stalk. It then has to attach the stalk to something: either a wall or another cell.
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In Caulobacter crescentus, the stalk formation is required for...
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and prior to cell division.
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What is Caulobacter crescentus a model system for?
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1. Unequal binary fission (dimorphism).
2. Co-ordination of developmental events |
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In Caulobacter crescentus, what is involved to control developmental stages?
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Phosporelay systems.
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What is Bdellovibrio bacteriovorus known for?
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for being a predator.
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What is the Bdellovibrio bacteriovorus cycle?
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It is a predator that bores into the periplasmic space and reproduces there. It interrupts CM and eats the cytoplasm of the host cell. Multiple fission events produce many flagellated cells that escape as the host lyses.
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Myxococcus xanthus does what?
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It has "wolf" behavior. The cells move in swarms. The first vegetative cells secrete slime trails for others to follow. They consume other microbes by releasing enzymatic fluids and antibiotics to kill the other microbes.
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What happens when the prey for Myxococcus xanthus is scarce?
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The cells pile up into aggregates and form fruiting bodies. They release myxospores that release the new microbes as a group. They only function as a group.
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How do the Myxococcus xanthus communicate?
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Cell to cell, mediated by 5 signals (A-E).
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How are Gram positive bacteria divided?
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Into two groups based on %GC in the genome. Low GC group is <50% GC (phylum firmicutes). and High GC group is >50% (phylum actinobacteria.
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Important genera in the High GC Gram +, and what they cause.
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1. Mycobacterium tuberculosis --> TB
2. Corynebacterium diptheriae --> diptheria 3. Propionibacterium acnes --> acne |
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Many species of the High GC Actinobacteria make...
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compounds that are the foundation of antibiotic and chemotherapy development.
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Many species of the High GC Actinobacteria resemble...
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fungi (filamentous growth to make hyphae and spores). Their names make them sound like fungi too.
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Many species of the Low GC Firmicutes include....
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pathogens (streptococcus, Staphylococcus, and Baccillus) and important microbes used in food (Lactobacillus, Lactococcus, and Leuconostoc).
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What are included in the Phylum firmicutes?
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all endospore formers and photosynthetic Gram + species.
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There are ______ different fermented milk products.
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over 400
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How is the milk fermented?
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By using lactobacillus or lactococcus.
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What are LAB's, and how do they work?
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Lactic acid bacteria; they are strictly fermentative, however the can ferment milk in the presence of O2 because they are aero-and acid tolerant.
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What happens when the acid production gets high in milk fermentation?
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It leads to curdled milk proteins. The curds and whey are seperated and the curds are compacted to make cheese.
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