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The processes that occur at the ER membrane in eukaryotic cells take place directly at the bacterial plasma membrane. Phospholipids are synthesised and inserted at the plasma membrane, and there is a protein translocation apparatus for translocation of proteins into the periplasmic space and insertion of transmembrane proteins into the plasma membrane.


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This is a very good question, and a very important topic in the healthcare and biological world. It is something that everyone should consider, as the answer is not as self-evident as it may appear. The responses here are excellent. I would like to add a few things from a healthcare perspective. This is the WHO recommendation on how to wash your hands. ...


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In the beta-Lactamase test, an inhibitor of beta-Lactamase is added to a sample of the culture medium. The inhibitor binds to the enzyme and changes its color, which is in direct correlation to the concentration of the beta-Lactamase. More b-lactamase means more inhibitor binding and this results in more color development leading to a higher absorption. So ...


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It is also an interesting thought that plasmids may be pieces of DNA that light be "parasites" on the bacterial cell which they use to provide resources for replicating themselves.


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Some bacteriophages adsorb on the pili. So the individuals carrying the F-element will be susceptible to these. F-plasmid encoded membrane protein PifA is responsible for the T7 resistance [See here]. The exact mechanism is not known If you see the list of references in the textbook chapter you will be able to trace the reference for a certain quoted fact ...


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The lipopolysaccharide layer of the Gram-negative bacterial cell wall is stabilised by divalent cations. Most recipes for disrupting E. coli cells include Tris-EDTA for this reason. I seem to just know this, so no reference at the moment. All nucleases require Mg2+, which is why there is EDTA in the stop buffer added to restriction digests. Carry-over of ...


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A lot of enzymes need metal ion in their active center (it is actually the metal ion which is taking part in the catalyzed reaction). These are manganese, magnesium, copper and so on. For DNAses the metal in the active center is magnesium and EDTA simply chelates this ions, making them unavailable for the enzyme and thus hinders the enzyme from working. ...


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ATCC- you can get most bacterial strains and cell lines there. Find P. denitrificans here: www.atcc.org/products/all/13543.aspx


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The exposure to environentally occurring Mycobacteria causes a immune response to these (mostly unspecific, since no real infections occur). It seems that immunizations with BCG in these individuals is causing either no, or only a very attenuated immune response This is shown in this ("BCG-induced increase in interferon-gamma response to mycobacterial ...


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If you were to take antibiotic resistant bacteria and kept them isolated, but fed well and so forth, how long would it take for them "forget" their resistance? It's not a matter of "forgetting". Bacteria are resistant if their DNA is such that it gives them a biology that renders the antibiotic non-lethal. You put a resistant bacteria in glycerol ...


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Lab strains of E. coli have been in use for many decades now. They have all retained a large number of genes encoding subunits of the flagellar apparatus and the chemotaxis system which confer absolutely no advantage under normal culture conditions. I conclude from this that the selective advantage conferred by losing "unused" genes must be very weak. Also, ...


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Antibiotic resistances in bacteria is commonly encoded by extrachromosomal DNA, the plasmids. These are circular pieces of DNA, which are much smaller than the hosts genome and which replicate independently from it. See the image from the Wikipedia: These plasmids can be transfered between different bacterial cells, which then also get resistant. Plasmids ...



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