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Definition
- constructed the first compound microscope and published the first illustration observed through a microscope. Coined the term "cell". |
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Definition
designed powerful microscoped allowing him to search for microbes in unexpected habitats |
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Term
Magnification vs. resolution |
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Definition
-magnification- an increase i nthe apparent size of an image to resolve smaller separations between objects
-resolution- the smallest distance by which two objects can be separated and still be distinguished |
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Term
Bright Fields vs. Dark Field Microscopy |
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Definition
- Bright field: generates a dark image of an object over a light background. Shows that light does not pass through. (you have to use a stain)
- Dark Field: Enables microscopes to be visualized as halos of bright light agianst darkness. (small images are visable) |
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Why would i use a fluorescence Microscope? |
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Definition
to observe the resolution of small structures |
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Term
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Definition
-transmission electron microscopy- electrons pass through the specimen, and reveals internal structures.
- scanning electron microscopy- electrons scan the specimen surface, reveals external features in 3D |
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Term
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Definition
- encloses the cytoplasm
- defines existence of the cell
- consists of phospholipids and proteins
- structural support
- detection of environmental signals
- secretions of virulence factors and communication signals
- ion transport and energy storage
- semi permeable membrane
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Term
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Definition
- covers the cell membrane
- confers shape and rigidity to the cells, helps withstand turgor pressure
- the bacterial cell awll is called the sacculus, consists of single interlinked molecules.
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Term
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Definition
- non membrane bound area of the cytoplasm that contains the chromosome in the form of looped coils
- prokaryotes have a nucleoid region that extends throughout the cytoplasm
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Definition
- essential for survival
- precents a cell from coming to equilibrium
- small uncharged molecules permeate the membrane by diffusion
- water tends to diffuse across hte membrane in a process called osmosis
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Term
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Definition
- molecules move along their concentration gradient
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Definition
- molecules move against their concentration gradient- requires energy (it takes energy to make energy)
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Term
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Definition
- the movement of a bacterium in response to chemical gradients
- attractants cause counter clock wise rotations
- flagella bundle together, push cell forward, "swim"
- repellents cause clockwise rotations
-flagellar bundle fall apart, tumble (bacterium briefly stops then changes direction
- the runs and tumbles cause a "random walk"
- receptors detect attractant concentrations (sugar, amino acids)
- attractant concentration increases and prolongs runs
-termed a "biased walk"
-causes net movement of bacteria toward attractants (or away from repellents) |
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Term
structure of peptidoglycan |
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Definition
- repeating disacharaide that is crosslinked with an amino acid bridge through NAM
- repeating units of NAM and NAG crosslinked with a pepto animo acid bridge
- consists of long polymers two disaccharides called NAG and NAM bound to a peptide of 4-6 amino acids (SUGAR)
- two parts, 1) Peptide 2) Sugar- the back bone
- the peptides can form crosslinks connecting the parallel glycan strands
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Term
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Definition
- bacteria with a thick cell wall
- cell envelope- everything outside the plasma membrane
- S-layer (not all species)- made of proteins
- thick cell wall- amino acid cross-links in peptidoglycan, 20-30 layers of peptidoglycan
- plasma membrane
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Term
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Definition
- bacteria with a thick cell wall |
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Term
D vs L amino acids... which is unique to gram positive |
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Definition
- D- does not fit through ribosome
- L- fits through ribosome
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Term
where is teichoic acid and what is it's purpose? |
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Definition
- teichoic acids- provide strength (unique to gram positive)
- located in the cell envelope
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Term
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Definition
- a capsule is not in every species it is made of polysaccharides (most pathogens have capsules)
- located in the cell envelope
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Term
why do i care that mycobacteria have mycolic acid? |
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Definition
- mycobacteria- complex cell
- excludes antibiotics and lots of nutrients-- results in malnutrition and slow growth
- mycolic acid- unusual membrane lipids
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Term
What is in the outer membrane of gram negative bacteria? |
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Definition
- a thin peptidoglycan layer consisting of one or two sheets covered by an outer membrane which confers defensive abilties
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Term
3 parts of LPS and which part s toxic and which part confers serotype specificity? |
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Definition
- 1. O polysaccharide- confers serotype specificity
- 2. core polysaccharide
- 3. lipid A - TOXIC0 overheating unit
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Term
Gram stain... which bacteria are purple vs pink and why |
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Definition
gram positive: purple, becuase iodine complex wiht crytal violet increases stain retention (thick cell wall)
gram negative: stain is removed when washed with ethanol becuase of their thin cell wall. (turns pink) |
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Term
Purpose of flagellum how does it work in general? |
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Definition
- a spiral filament of pretein monomers called flagellin
- the filament is rotated by a motor driven by the proton motive force (basil body and hook curves into flagella)
- assists prokaryotes in movement
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Term
Facilitate Transport vs active transport |
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Definition
- facilitate trasnport (passive transport)- helps solutes move across a membrane from a region of high concentration to one of lower concentrations.
- it does not require energy and cannot move a molecule against its gradient
- Active Transport- requires energy. movement of molecules against its gradient
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Term
Coupled transport- Symport vs. Antiport |
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Definition
- coupled transport systems are those in whcih energy released by moving a driving ion down its gradient is used to move a solute up its gradient
- symport- two molecules travel in the same directon
- antiport- two molecules move in the direction opposite to the driving ion
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Term
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Definition
- specialized molecules secreted to bind ferric ion and transport it into the cell.
- the ion is released into the cytoplasm and reduced to the more useful ferrous form
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Term
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Definition
- a process that uses energy to chemicall alter the substrate during its transport
- PTS (phosphotransferase system (present in all bacteria)).
-unses energy from phospheonolypyruvate (PEP) to attatch a phosphate to specific sugars
- the system has a modular design that accommodates different substrates |
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Term
Spontaneous generation- how/who disproved the theory. What was the experiment? What was the potential flaw in the experiment? |
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Definition
- The theory that living creates could arise without parents
- francesco Redi- showed that maggots in decaying meat were offspring of lies
- lazaro spallanzani- showede that a sealed flask of meat broth sterilized by boiling failed to grow microbes
- louis pasteur- discovered the microbial basis of fermentation
-devised "swan neck" flask
-showed that, after boiling, the contents reain free of microbial growth despite access to air
- his flaw was that the organisms that grew in pasteurs flask were spires that were not killed by boiling |
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Term
selective vs differential media |
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Definition
- selective- favor the growht of one organism over another (there is either growth or not growth)
- Differential- expoit differences between two species that grow equall well
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Term
Growth curve and what occurs in each phase |
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Definition
- Growth curve- expontential growth does not last forever.
- 1. lag- bacteria are preparing their cell machinery for growth
- 2. log
- 3. stationary phase- where secondary metabolites are aborbed
- 4. Death phase- everything is dying
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Term
Biofilm... why do i care? |
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Definition
- Biofilms- specialized surface-attached communities formed by bacteria
- 1. attachement monolayer
- 2. micocolonies
- 3. exopolysacharides production
- 4. mature biofilm
- 5. dissolution and dispersal
- antibiotics cannot get through the biofilm- provides a unit of safety
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Term
What is an endospore? When does it appear? Name one genus of bacteria that makes spores. Do spores grow? Why do I care? How do i get rid of them? Why do i care? |
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Definition
- endospore- only gram positive makes spores- (bacillus)
- heat resistant
- appear during starvation- an asymmetrical cell division process that produces a forespore and ultimately an endospore
- THEY DO NOT GROW
- Metabolically inactive so you have to kill them wiht a combination of high pressure and temperature (steam autoclave). They have everything to create a new bacteria but they are METABOLICALLY INACTIVE
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Term
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Definition
- the sudden infusion of large quantities of a formerly limiting nutrient
- can lead to a bloom of microbes, which threaten the existence of competing species.
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Term
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Definition
-phile- like
-phobe- dislike
tolerant- tolerate |
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Term
Extremophiles, psychrophiles, vs mesophiles vs thermophiles. What is the main cellular structure that changes between the optimal growth temps of these. Why can psychrophiles survive at thermophile temps? |
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Definition
- psychrophiles 0-4 C
- mesophiles- 15-45 C
- thermophiles 40-80C
- hyperthermophiles 65-121C
- extremophiles- organims ability to survive in a ecological niche outside the normal growth conditons
- becuase they are tolerant- they can only live in an environment between 0-20C
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Term
does internal pH change for alkaliphiles like the internal temp of a thermophile? Why? How do bacteria mangae the extreme pHs? |
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Definition
- enzymes activites exhibit iptima, minima and maxima with regard to pH
- bacteria regulate internal pH range
- wake acids can pass through membranes
-disrupt cell pH homeostasis and thus kill the cell
- IF YOU DISRUPT THE INTERNET pH YOU WILL KILL THE CELL
- the internal pH does not change if it does the cell will die
- under extreme conditoons the cell can use the N+/H+ antiporter to bring protons into the cell in exchange for expelling Na+.
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Term
classification of microbial responses to oxygen |
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Definition
- strict aerobes- can only grow in oxygen
- microaerophiles- grow only at lower O2 levels
- strict anaerobes- die in the least bit of O2
- facultative anaeroves- can live without without oxygen
- aerotolerant anaeroves- grow in oxygen while retaining a fermentation-based metabolism
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Term
sterilization vs disinfection vs antisepsis vs sanitation |
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Definition
- Sterilization- killing of ALL living organisms
- disinfection- killing or removal of pathogens from INANIMATE OBJECTS
- antisepsis- killing or removal of pathogens from the SURFACE OF LIVING TISSUES
- sanitation- reducing the microbial population to safe levels.
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Term
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Definition
- not sterilization- it is the partial sterilization of foods at a temperature that destroys pathogens and more organisms, without changing the chemistry of the food. (ex: the pasteruizaton of milk)
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Term
Joseph Listers claim to fame |
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Definition
- developed carbolic acid to treat wounds and lcean surgical instruments
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Term
Define antibiotic. Why do I care? And why do i care that i take them all? |
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Definition
- antibiotics- chemical compounds synthesized by one microbe that kills or inhibits the growth of another microbial species.
- if you stope takng them they will not completely kill the microbial species.
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Term
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Definition
- and obligatory intracellular parasites- contains DNA or RNA or double stranded
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Term
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Definition
coats the outside of the virus |
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Definition
determined by specific host attachment sites and cellular factors. |
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Term
lytic vs lyscogenic cycles |
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Definition
- lytic cycle- bacteriophage quicly replicates, killing host cell.
- lysogenic cycle- bacteriophage is quiescent, integrates into cell chromosomes, as a phosphage. can reactivate to become lytic
- In general, events that threaten host cell survival trigger a lytic burst
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Term
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Definition
- composed of repeated protein subunites
- this maximized the capacity while minimized the required number of genes
- the capsid packages the viral genome and delivers it into the host cell
- different viruses make different capsid forms
- symmetrical or asymmetrical |
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Term
transduction? Prophage... |
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Definition
- transduciton- transpers DNA via phage particle
- prophage- The genetic material of a bacteriophage, incorporated into the genome of a bacterium and able to produce phages if specifically activated.
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Term
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Definition
-DNA or RNA
-single or double stranded
linear or circular
- include genes encoding viral proteins
-capside
-envelope proteins
-any polymerase not found in host cell |
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Term
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Definition
- DNA viruses- can utilize the host replication machinery
- RNA viruses- use an RNA-dependent RNA-polymerase to transcive their mRNA
- retroviruses- use a reverse transciptase to copy their genomic sequence into DNA for insertion in the host chromosome.
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Term
six steps of the animal virus life cycles |
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Definition
- 1. attachment: viruses attach to cell membrame
- 2. penetration- by endycytosis or fusion
- 3. uncoating by viral or host enzymes
- 4. biosynthesis: production of nucleic acid and proteins
- 5. maturation: nucleic acid and capsid proteins assemble
- 6. release by budding (enveloped viruses) or rupture
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Term
RNA viruses use an ___-dependent RNA polymerase to transcribe their mRNA |
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Definition
- RNA- dependent RNA polymerase.
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Term
retroviruses use a _________ to copy their genomic sequences into DNA |
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Definition
- use a reverse transciptase to copy their genomic sequence into DNA |
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Term
HSV primary infection is _______ but latent infecton can occur within ________. Why is this important to you? |
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Definition
- primary infection is epithelial
- but latent infection can occur within neurons of ganglia
- this is important because it can be triggered by stress
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Term
Poliovirus is transmitted by ____ route. Most cases result in mild _________. __% result in paralysis. First vaccine was the Salk vaccine which uses a _____ viral particle whereas the Sabin vaccine uses a ____ virus. |
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Definition
- fecal-oral route
- gastrointestinal infection
- 1%
- innactive polio virus
- attentuated polio virus
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Term
Infuenza A has a __ genome. Why is this imporant? H stands for _____ while N stands for ___ and why do I care? |
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Definition
- segmented genome- eight separate linear (-) strands of RNA
- Hemagglutinin
- Neuraminidase
^^ two major envelope proteins. H1/ N1 viruses. |
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Term
What is reverse transciptase and why do I care? |
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Definition
- copies the RNA genome to DNA
- 1. DNA synthesis from the RNA template
-primed by the host tRNA
- 2. RNA degradaton: via RNase activity
- 3. DNA-dependent DNA synthesis
- -generates a dsDNA
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Term
Contast acute, lantent and persistent viral infections. Provide and example for each |
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Definition
acute- short period of time, influenza
persistent- disease processes ovvurs over a long period; generall is fatal (ex HIV)
latent- virus remians in asymptomatic host cell for long period. (ex shingles, HSV) |
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Term
Nonvirus and Rotavirus cause ___ and are especially fatal in _____ of the ______ world. |
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Definition
- gastroenteritis
- children
- developing countries
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