Intro Flashcards
gram + and gram - differ by their….
- cell wall structure
- cell wall has thick peptidoglycan
- cell wall has thin peptidoglycan and is a unique outer membrane
acid fast staining is used to detect….
mycobacterium (TB and leprosy)
most common endospores?
- bacillus
- clostridium
bacterial cell walls are made up of….
peptidoglycan (n-acetyl muramic acid and n-acetyl glucosamine which are gram negative) some also have teichoic acid which make it gram positive
Gram - cell wall contains….
- lipopolysaccharide (endotoxin)
- this signals immune system
- contains Lipid A and O antigen
Small molecules and ions can cross gram - cell wall via….
porins
What bacteria lack a cell wall?
- mycoplasma (variable shape, small organisms)
- PCN will not work bc pcn works on cell wall degradation
amphitrichous
lophotrichous
peritrichous
- single polar flagella on opposite sites (2 on each side)
- multiple polar flagella on opposite sites
- flagella distributed over entire cell
Pili that allow surface attachment are termed
fimbriae
What are plasmids?
- circular, supercoiled dsDNA (extrachromosomal DNA)
- related to antibiotic resistance
Chromosome forms the nucleoid, which is….
single circular double stranded DNA
Cytoskeleton
-internal protein framework
Storage granules
- accumulations of polymers
- glycogen, poly-B-hyrdroxybutyrate
Gas vesicles
-controlled to provide buoyancy
Main example of a metachromatic granule?
Corynebacterium diptheriae
Shape of strep
chain
shape of staph
grape like cluster
cocci
round
bacilli
rod
how do bacteria divide?
binary fission
Lag Phase
Log phase
stationary phase
death phase
- no growth occurs
- growth rate exceeds death rate, production of primary metabolites
- growth rate equals death rate
- death rate exceeds growth rate
psychrophiles
mesophiles
thermophiles
halophilic
-5 to 15
25-45
45-70
salt loving
aerobic
anaerobic
microaerophilic
facultative
- O2
- CO2
- requires low O2 concentrations
- both
acidophiles vs
alkaliphiles
pH<5.5
pH>8.5
icosahedral virus shape and examples
- made up of equilateral triangles
- polio, rhino, adeno
capsid
protein layer that surrounds and protects nucleic acids made up of capsomeres
enveloped virus structure and examples
- icosahedral or helical structure surround by a lipid bilayer
- flu, hep C, HIV
helical virus structure adn example
- has a capsid w/ a central cavity
- tbacco mosaic virus
function of bacteriophage/phage
-virus that attacks bacteria and injects nucleic acids without going into the cell directly
virion
- completely assembled, infection virus outside its host
- whole virus goes into the cell
how are retroviruses replicated?
indirectly through a DNA intermediate using a reverse transcriptase enzyme (RNA to DNA)
Neuraminidase cleaves ( ) from the cell surface
sialic acid, facilitating viral release from infected cell
Hemagluttinin
molecule on virus surface that bonds with sialic acid
H1/H2/H3 do what?
-find particular sugars in the respiratory tract
What is antigenic drift?
- mechanism for variation in viruses
- accumulation of mutations within genes that code for antibody binding site that were originally targeted against the present strain, making it easier for the virus to spread
- results in new H/N
