Micro Final Old Exam Questions Flashcards
microbe
a living organism that requires a microscope to be seen
What differentiates prokaryotic from Eukaryotic?
absence of membrane bound organelles
What tool was critically for advancing the germ theory?
microscope
Viruses and cells always contains?
DNA or RNA
Beneficial products of microorganisms
1.Nitrogen Fixation
2.Synthesis of vitamins
3.production of fermented foods
Germ Theory
- disease is caused by transmissible germs
A microbe that causes sickness in healthy people is what?
primary pathogen
Koch’s Postulate
- Pathogen isolated from disease host
2.Pathogen grown in pure culture
3.pathogen introduced into healthy host and disease occurs - Same pathogen is isolated in newly infected diseased host
What thing can’t be grown in a pure culture and can pass through tiny-pored filter
virus
During which phase of an infectious disease do disease symptoms begin to subside
decline phase
The ability of the microbe to cause disease
pathogenicity
Relationship between the microbiota and the human host
mutualistic
What impact will deforestation for a new suburban housing project have on disease transmissibility?
It will bring vectors and reservoirs closer to humans
Sequelae
A condition that arises from the complication of a previous disease
Virulence
degree of severity of a disease
symptom
something felt only by a patient
parenteral route
Pathogen enters the body through insect bite or needle injection
Classes of cytoskeletal Proteins
- intermediate filament
2.Actin Filament
3.Microtubules
Microaerophiles
they need oxygen for growth but lack enough enzymes needed to detoxify reactive oxygen species
Pilus
-a protein extension that allows for the transfer of DNA between two bacteria
Ribosomes are associated with which endomembrane organelle
endoplasmic reticulum
Psychrophile
10-20 degrees
Mesophile
20-40 degrees
Thermophiles
40-50 degrees
Hyperthermophiles
70-100 degrees
autotroph
produces carbohydrates
heterotroph
breaks down carbohydrate to generate CO2
Lithotroph
organism gains it’s energy from the oxidation of ferrous iron to ferric acid and hydrogen sulfide to sulfuric acid
Why are biofilms formed?
attach to a surface in an area where food is plentiful
Why do strict anaerobes die in oxygen?
They are vulnerable to ROS
What is needed for endospore formation?
1.peptidoglycan synthesis
2.Acid Synthesis
3.Calcium Transport
Not exopolysaccharide formation
LD50 means what
-lethal dose at 50% mortality
paramecium is classified as what
ciliate
What is a unique feature of the influenza viruse genome
a segmented RNA genome
Protease inhibitors are common antiviral drug targeting
HIV
Tissue Tropism
the range of tissue types a virus can infect
Which of these models of action of antivirals would have the broadest spectrum of activity: disruption of viral mRNA,DNA synthesis disruption, enzymes to degrade reverse transriptase, and membrane disruption
disruption of mRNA
The host range of a virus depends on which host factor
the specific surface receptors found on host cells
Blocking this enzyme/process would have little to no effect on influenza
DNA Polymerase
In the lifecycle of a tropanosome, which form proliferates within the definitive host
slender
How are cells damaged during a virus infection?
Replication and subsequent release of virus particles can lead to impairment of cellular function or cell destruction
Which mechanism does an ameba use for locomotion?
pseudopods
Why must the genome of HPV enter the nucleus for replication?
The DNA genome of HPV can only be replicated in the nucleus where host DNA polymerase is found
an enveloped virus obtains its envelope from what
the host cell
Which of the following would most likely to stop transmission of plasmodium falciparum and P. Vivax to humans: access to clean drinking water, providing mosquito netting, checking for ticks after waling in wooded areas, and eliminating bedbugs from sleeping quarters
Mosquito net
Ameba proteus, a lobed ameba, most likely moves using what?
cytoplasmic streaming
single celled eukayotic microbe proliferating by mitosis is undergoing what?
asexual reproduction
After budding of new influenza virions, the host cell does what?
is destroyed
After phage genetics have integrated into the bacterial chromosome, the phage is called a what?
prophage
when comparing sexual to asexual reproduction, the advantage of sexual reproduction is what?
increases genetic diversity, which may be useful in a changing environment
An infectious particle with an RNA genome and no capsid
viroids
Viruses can infect what?
bacteria, eukaryotic cells, and archea
What is caused by misfolded protein?
1.Creutzfeidt-Jakob disease
2.Kuru
3.Scrapie
The function of apical complex on a merozoite form of plasmodium falciparum is to do what
to allow the merozoite to enter RBCs
Segmented Influenza RNA Genome is capable of what?
reassortment
Which of the following stages of the influenza infection cycle is inhibited by tamiflu?
the cleaving of the host receptor and release of the virus by budding
West Nile Virus is capable of of infecting many different organisms. This means it is a what?
has a broad host range
Why is it harder to treat an infection in an human caused by eukaryotic microbes than it is to treat bacterial infections?
The cells found in fungi and humans are more similar to one another than cells of bacteria and humans
Some human aspergillus and histoplasmosis infection is caused by what?
inhalation of fungal spores
The blood parasite babesia microti causes what?
Babesiosis
Prion disease can be acquired by what?
- the misfolding of an endogenous protein
- genetic inheritance
3.transmission by an infectious protein
What type of bacteriophage infection results in imediate death of the host cell?
Lytic
Trypanosoma Brucei that causes african sleeping sickness is carried by what?
tsetse flies
Anthropods include what of the following: fleas, lice, mites, tapeworm
fleas, lice, mites
Why are their so few antiviral agents compared to antibacterial agents?
viruses use function of the host to replicate themselves, so achieving selective toxicity id difficult
Why are so few HIV virons released in the blood are actually infectious?
reverse transcriptase has a high error rate
A good target for antifungals is what
ergosterol synthesis, a cholesteral specific fungi
What enzyme ensures HIV infection is permanent?
integrase
If the hemagglutinin spike were removed from the influenza viral envelope, then the virus would not be able to do what?
integrase
How is HPV able to keep its genome so small?
overlapping reading frames
What process is used to remove pathogens from hospital beds?
disinfection
Why does it take so long for H2O2 to remove blood?
This type of disinfection procedure is best completed at colder temperatures
Standard conditions for sterilization at 121 degrees Celsius and 15 psi for 20 minutes
autoclaving
What is the purpose of low temperatures
inhibit growth
stop microbial metabolism
preserve microorganism
NOT KILL
What kind of sterilization doesn’t use heat?
filtration
HAART is used to treat what?
HIV
What is a good target for antifungal and is a cholesteral specific fungi
ergosterol
What in a cell wall gives bacteria gives selective toxicity
peptidoglycan
The trachea has how much bacteria
10-100 bacteria per 1,000
What is carried out by microbes in the SI
-digestion
-immune system stimulation
-promotion of tissue development
anerobes colonize an infants mouth when?
once teeth emerge
P.aeroginosa in the lungs of a patient with cystic fibrosis is what?
biofilm
Streptococcus mutans and streptococcussalivarius adhering to oral surfaces is what?
biofilm
Vegetation of a patient with a heart murmur is what
Biofilm
Faecalibacterium prausnitsil and bacteroides thetaiotaomicrom are involved with what?
butyrate and metabolism of complex carbohydrates
Lipopolysacharides, flagelin, and double stranded DNA are microbe- associated molecular patterns recognized by what
pattern recognition receptors
Why do people take probiotics?
restore balance to the microbial community
Which microbe resevoir has largest anerobe to aerobe ratio
intestines
Which of the following can affect a fetus?
Influenza, Listeria Monocytogenes, S. Aureus, Hep A
Listeria Monocytogenes
a germ free animal is more or less susceptible to pathogen infection?
more
What is used to study microbiota relationships in the labratory?
gnotobiotic animals
Blood brain barrier is composed of what?
really tight junctions
Why is it hard to trait an infection in the brain?
-abx can’t penetrate blood brain barrier
What organism can cross the blood brain barrier
neisseriameningitidis
In an AB subunit A is responsible for what and B is responsible for what
A=toxicity
B=binding to target cells
What are some toxins
-superantigens
-Ab toxins
-Plasma membrane disruption toxin
What are ways for bacteria to evade phagocytic digestion
1.escape
2.inhibiting lysosome and phagozome fusion
3.Survival in phagosome
genes of what evolved, duplicated, and mutated to serve protein secretion mechanisms
-pili
Why are biofilms important clinically
biofilms can persist against host defenses
How can shigella and listeria are able to move cell to cell without being detected by the host immune system?
they produce an actin tail that propels them cell to cell
Pathogenicity island
-a segmented genome that increases the fitness of a pathogen during interaction with the host cell
What does E. Coli labile toxin do?
-an AB toxin
-reverse the absorption process in intestines
-causes severe diarhea
capsule
-a thick polysacharide layer that envelopes a bacteria cell and enables it to avoid host’s immune system
Most pathogenicity islands are aquired by what?
horizontal gene transfer
Transduction
a bacterial cell infected by a phage and incorporates the phage genome into it’s own
