Structure, Function, Reproduction, Classification Flashcards
Which microbial association is described by the host not being harmed or benefiting from the organism? (shelter and food)
commensalism
Which microbial association is described as “obligatory and dependent” where both members benefit?
mutualism
In which microbial association is the host harmed and the organism benefits?
parasitism
An example of _ relationship is with bacteria that lives in our ears simply because it is warm and full of nutrients
commensalism
Most relationships that we have with organisms is _
mutualistic
Why are we hesitant when prescribing antibiotics?
Because of all the mutualistic relationships, we don’t like having to destroy those organisms that result from over prescription
Which microbe is described by “prokaryotic, no nuclei, single celled organisms, live singly, in pairs, chains, clusters”?
bacteria
Which microbe is described by “acellular, not visible by microscope, obligatory microbes composed of genetic material surrounded by protein coat”?
viruses
Which microbe is described by, “eukaryotic, possess a nuclei and cell wall, organelles, obtain nutrients from other organisms”?
fungi
Which microbe is described by “eukaryotic, single-celled organisms, possess a nuclei”?
protozoa (typically a parasite)
Which microbe is described by, “eukaryotic, multicellular, possess a nuclei, visible with the naked eye”?
Helminths (typically a parasite)
Why is is helpful that bacteria are prokaryotic?
because we are eukaryotic so Px medication does not harm the host
Which infection is more serious, bacterial or viral?
bacterial (ex. bacterial meningitis)
When developing drugs for fungi what part of the cell are we targetting?
the cell wall
T/F: antifungal medications are associated with far more adverse effects than antibacterial medications because they are eukaryotic
True
_ are what make certain bacteria are able to resist antibiotics
plasmids
_ can be shared with other bacteria to convey how to resist antibiotics, therefore it is important to always take the full dose Rx to knock the bacteria out
plasmids
“_” means pairs
step
“_” means a cluster
staph
An example of streptococci is _
strep throat
T/F: shape of the colony, margin/edge, elevation, surface texture and pigmentation are all important to identification
True
Polar- Vibrio spp. is an example of a bacteria with _ amount of flagella
Single (ONE)
Polar- Spirillium spp. is an example of a bacteria with _ amount of flagella
double (TWO)
Peritrichous- Escherichia coli spp. is an example of a bacteria with _ of flagella
a lot
T/F: A bacteria with a flagella has a greater ability to make us sick as opposed to ones that do not
True
What part of the bacteria facilitate the formation of biofilms?
Fimbriae
_ act as adhesions, binding to specific host cells receptors - important role in adherence, a critical step in infection
Fimbriae
_ - used to transfer DNA from one bacteria to another (facilitate the movement of plasmids)
conjugation pili
_ is a protective substance surrounding come bacteria, normally made of polysaccharides, the presence/ absence can be used for classification
Glycocalyx
_ is really good for holding onto inorganic material such as catheters and IV lines and are very hard to penetrate through with antibiotics
slime layer
What is a slime layer?
It is sticky and loose - prevents dehydration, allows bacteria to bind to surfaces and form a protective layer encapsulating colonies of bacteria
T/F: capsules are shared amongst bacteria to be able to survive antibiotics
False, capsules facilitate adherence and impairs phagocytosis
T/F: capsulated bacteria is better at making us sick
True
T/F: the leading cause of pneumonia in Canada is encapsulated streptococcus pneumonia
True
_ are the defensive strategy against hostile or unfavorable environmental conditions (driven by nutrient supply)
Endospores
T/F: Endospores are metabolically active - resistant to heat, cold, drying, chemicals and radiation
False, they are metabolically dormant
The _ counters the effects of osmotic pressure when enters blood stream (for a bacterium)
cell wall
Which bacterial infection is an exception and does not have a cell wall?
TB
T/F: our immune systems are really good at recognizing the peptidoglycan layer of the cell wall and targeting it
True
Bacteria that retain primary colour dyes and become purple colour post-gram stain are gram _
positive
Bacteria that are easily decolorized and take on a pink/red colour post-gram stain are gram _
negative
Gram_ have thick, dense, relatively non-porous walls, while gram _ have thin cell walls surrounded by an outer membrane
- positive
- negative
Which gram bacteria contain LPS (composed of Lipid A) in their cell wall?
Gram- negative
_ is a potent endotoxin causing fever, vasodilation and inflammation - can induce shock and blood clot formation
LPS Lipid A
What type of stain can be done if a mycobacterial infection is suspected?
Acid fast stain, this type of bacteria has a waxy material in their cell wall that retains the alcohol stain
What is a clue that we need to conduct an acid fast stain because the patient may have a mycobacterial infection?
If they have been put on antibiotics multiple times and still have not gotten better
_ is highly reactive and toxic to bacteria unless it is inactivated by enzymes produced by bacteria
molecular oxygen
Enzymes that bacteria use to detoxify reactive O2 products include:
- catalase
- peroxidase
- superoxide dismutase
_ bacteria require oxygen to survive therefore they have all 3 enzymes used to inactivate molecular oxygen
obligate aerobes
_ prefer to grow in the presence of oxygen, but can also grow without, produce catalase and superoxide dismutase (flexible)
facultative anaerobes
_ tolerate low amounts of oxygen (i.e stomach), produce superoxide dismutase (fussy)
microaerophiles
_ cannot tolerate O2, lack enzymes to manage toxicity and thus requires special growth conditions (hate o2)
obligate anaerobes
Why do we need to collect two sets of blood samples form two different sites?
one anaerobic and one aerobic
What are the two ways bacteria reproduce?
- asexual reproduction (binary fission)
2. sexual reproduction (requires conjugation pili)
_ intracellular bacteria require host cell to live; cannot make their own energy
obligate
_ intracellular bacteria are able to survive phagocytosis; grow and reproduce within immune cells, shielded from antibodies and other immune defenses, and employ specialized mechanisms to protect against lysosomal enzymes produced within phagocytic host cells.
facultative
[Viruses]- _ intracellular pathogen cannot replicate independently, must replicate inside host cell
obligate
[Viruses]- _; lack cell membrane, composed of only a few organic molecules. Possess DNA or RNA, supported by a protein capsule or “capsid” that provides both protection and recognition sites that bind to receptors on host cells.
acellular
some viruses also possess an _ from host cells which facilitates entry into host cells, in such cases cellular membrane proteins are replaced with virus-derived proteins.
envelope
Viruses _ reproduce independently; they lack _ necessary for replication and do not possess _ for protein synthesis .
- cannot
- enzymes
- ribosomes
What are the 5 steps of viral replication?
- attachment
- entry
- synthesis (DNA synthesis occurs in the nucleus, RNA synthesis in cytoplasm)
- assembly into virions
- release from host cell (budding or lysis/excocytosis)
What is the most violent method of virus release from host cell?
Lysis, it explodes from the cell, they tear it open to make their way to other tissue
_ infection: alteration of antigenic specificity of cell surface due to presence of virus _; host cell function is intact leading to gradual, prolonged release of _
- persistent
- glycoproteins
- progeny viral particles
_ infection: persistence of viral _ in cell with no virus progeny produced - the _ virus can be reactivated months to years later resulting in a productive infection
latent
genome
latent
Which type of viral infection cannot be cured?
latent infections
What is an example of a latent viral infection?
herpes
_: integration of viral genome into host cell chromosome may result disruption of host cell metabolic functions including _ and _ resulting in the induction of tumors
transformation
cell growth
replication
What is the most dangerous type of viral infection?
The transformation because they cause a variety of cancers due to changing of the host cell
_ is what causes the fever, runny nose associated with the upper respiratory viral infections.
Cell Lysis
