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32 Cards in this Set
- Front
- Back
State the four points to Koch's postulates that aimed to find the causative agnets of a particular disease
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1) the organism must be present in all cases of the disease
2) the organism must be isolated from the infected person and grown in pure culture 3) The organism from pure culture must be able to reproduce the disease when introduced into a susceptible animal 4) Again, the organism must be isolated from experimental animal |
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What is the problem with Koch's postulates as it applies to today?
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We are running into problems at step 3. Not all diseases that we as humans have are replicatable in animals, and vice versa (not as easy to transcend that line from human to animal)
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What would a eukaryotic cell stain on gram staining?
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Gram - because it has no peptidoglycan (peptidoglycan is only in bacteria)
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True or false - both gram + and - bacteria are capable of having polysaccharide capsules?
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TRUE
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True or false - many capsules are antiphagocytic because they can resemble things on our own cells (molecular mimicry?)
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TRUE
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Flagella (are/aren't) highly antigenic
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ARE
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Discuss the two types of flagella?
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1) Peritrichous - all over the course of the cell
2) Monotrichous - assemble into one polar direction at one end |
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In gram positive bacteria their nucleus is attached to a bit of membrane called the ________
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mesosome
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Spores are made only by gram (+/-) and more specifically by ______ and ______
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GRAM POSITIVE, Bacillus & Clostridium
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The equivelant of the nucleus in the prokaryote is the _______
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nucleoid
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_______ is a response by some gram positive bacteria to starvation conditions
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Sporulation
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During sporulation one of the _______ condenses, and gets wrapped in layers of material deposited around it
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chromosomes
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_______ acid is attached to the lipid molecule in the cell whereas _______ acid is attached within the cell wall itself
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lipoteichoic, teichoic
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One of the amino acids in your crosslinking peptide chain of peptidoglycan should be a ____amino acid to ensure crosslinking with another group
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DIAMINO
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Explain the purpose of the thick peptidoglycan layer offering osmotic protection for the gram positives?
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Protects their integrity and confers their shape, but with osmotic protection the cell will not respond to hyperosmolar or hypoosmolar environments (which would cause other cells to shrink or bloat up)
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In prokaryotes, membrane bound organelles are ______
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absent
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In prokaryotes, cell wall is _______, while in eukaryotes cell wall is _______
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rigid peptidoglycan, absent
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Ribosomes in eukaryotes are _____ than ribosomes in prokaryotes
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larger
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Flagella functions in ______ & ______
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motility & chemotaxis
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Fimbria (pilli) function in ______ & _______
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adhesion & attachment
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As far as classifications of bacteria, there are phenotypic, DNA homologies, and ribosomal RNA. What is easiest?
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ribosomal RNA homologies are much less tedious to perform than DNA homologies. rRNA results are very quick and accurate, and thusly more popular
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Spores are metabolically _________
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inactive
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When conditions are again favorable for growth, the spore will __________ and develops into a ________ cell.
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germinate, vegetative cell
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_____________ reside on the inner face of the gram negative outer membrane and serve to dock on to the thin peptidoglycan layer, preventing the outer membrane from floating away
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Helical lipoproteins
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Lipopolysacchardies are found on the (inner/outer) leaflet of the (inner/outer) membrane
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outer, outer
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Teichoic acid & lipoteichoic acid are found only in ________
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gram positive bacteria
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The function of the outer membrane is as a size exclusion barrier of ______ MW
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800 MW
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State the components of LPS
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Lipid A (the endotoxin) that is burried into the outer leaflet of the OM, this is linked to the core polysaccharide (the part of the CPS in closest proximity to lipid A is going to be the KDO sugar). Attaching to the core polysaccharide will be the O antigen
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Give two reasons why gram negative bacteria are more resistant than gram positives to bile acids, detergents, and many hydrophobic antibiotics
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1) Only gram negatives have MDR pumps (multi-drug resistance pumps) which span out across the cytoplasmic and outer membranes, pumping out hydrophobic antibiotics and detergents
2) Because they are so tightly/densely packed at their outer surface of their outer membranes which end up decreasing the permeability of the outer membrane of the gram negative bacteria |
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What is found in the periplasmic space?
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Enzymes that cleave antibiotics and peptidoglycan layer
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What are the 4 functions of the cytoplasmic membrane (break down into subcategories as well)
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1) Metabolic pathways
*ATP generation *Electron transport chain *cell wall biosynthesis 2) Sensing their environments *signal transduction *chemotaxis 3) Nutrient transport channels *specific transporters mediate uptake of sugars, vitamins, peptides, and amino acids 4) Efflux pumps *Macromolecules *Hydrophobic agents (the MDR efflux pump) |
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The multidrug efflux pumps have a lot of homology to the pumps/things that pump out _____________ drugs from ____ cells
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anti-neoplastic drugs (chemotherapeutics), cancer cells
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