Test 1: Lecture 1 and 2 intro and structure Flashcards
prokaryote vs eukaryote
prokaryote→ no nucleus, single cell organism, cell wall
eukaryote → nucleus, can be single or multicellular organisms
gram + bacteria are ___
gram - bacteria are ___
purple
pink
fastidious bacteria are ___
difficult to grow in a lab
we know little about them
a bacteria that is microareophilic likes ___
high CO2
a bacteria that has facultative growth means
prefers aerobic( O2) or anaerobic (no O2) but will grow in the other if it has to
a bacterial cell has a complex structure with highly
___ traits AND highly ___ trait
conserved
plastic
a bacteria is what type of cell?
prokaryotic
no nucleus → nucleoid
cell wall of mycobacteria have ___
mycolic acid
lipo-arabino-mannan
what kind of bacteria?
Gram +
Outer layer: Thick layer of peptidoglycan
• teichoic acid (bound to peptidoglycan)
• lipoteichoic acid (anchored in cytoplasmic membrane)
Inner layer: Cytoplasmic Membrane
gram + or Gram - have a LPS outer layer?
gram negative
Gram stain purple ___
gram +
gram stain pink
gram negative
Gram + Have a thick outer cell wall
made of ___
peptidoglycan
gram + peptidoglycan layer is covered in ___
lipoteichoic acid and teichoic acid
Staphylococcus spp, Streptococcus spp. would stain ___
purple
gram +
E. coli, Salmonella and enterica would stain ___
pink
gram negative
gram negative have an outer and inner membrane with a thin ___
layer of peptidoglycan
gram - bacteria cell wall is covered by ___ that can be seen by ___
(LPS) lipopolysaccharide
TLR4
what does TLR4 see and what kind of bacteria?
LPS
gram negative
steps of Gram stain
if you stopped a gram stain at the iodine treatment stage what color would gram + and - bacteria be?
both purple
have not gone through the decolorization and counter stain phase
___ and ___ are found in the outer layer of a gram + bacteria
teichoic acid -(bound to peptidoglycan)
lipoteichoic acid- (anchored in cytoplasmic membrane)
another name for peptidoglycan
murein
___ is a polymer made of sugar and amino acid components
peptidoglycan (the meat of the sandwich)
Alternating subunits of ____ and ___ that form cross links inside peptidoglycan
n-acetyglucosamine (NAG)
n-acetylmuramic acid (NAM)
they are the carbohydrate part of peptidoglycan
Gram ___cells contain up to 10x the amount of peptidoglycan than Gram ___ bacteria.
positive
negative
peptidoglycan is critical for providing structural strength and
resistance to ___ pressure.
cytoplasmic osmotic
what TLR see peptidogylcan?
TLR2
layers of the gram - cell wall
Inner most layer: Cytosolic membrane (phospholipids)
Middle: Thin layer of peptidoglycan within the periplasmic space
- *Outer Layer:** Outer membrane made of phospholipid and
- *lipopolysaccharide (LPS)**
gram negative
another name for LPS
endotoxin
LPS is made of what three parts
O antigen (variable portion)
Core domain (linking portion)
Lipid A (anchor)
LPS Prevents penetration of harmful substances into the bacterial cell such as ___
(i.e. bile salts)
two bacterial functions of LPS in Gram + are ___
Stabilizes outer membrane
Prevents penetration of harmful substances into the bacterial cell (i.e. bile salts)
what part of the LPS is seen by the TLR?
the core domain (linking portion)
what does TLR4 see?
LPS on gram negative bacteria
3 things LPS cause in the host
seen by TLR4 → innate immune reaction
cause fever
competes for ADH receptor → makes the host very thirsty (nephrogenic diabetes insipidus)
___ on gram - cell walls cause you to be thirsty, How does this work?
LPS
competes with ADH receptor
can’t tell the body you are not thirsty
DNA exists in two states in the Bacterial Cell :
The Circular Bacterial “Chromosome”
Mobile Genetic Elements
DNA exists in two states in the Bacterial Cell :
The Circular Bacterial “Chromosome”
Mobile Genetic Elements
bacterial chromosomes are ___ shaped
circular dsDNA
usually only one that is several million base pairs long
what is a bacterial chromosome mainly made of?
housekeeping gene
critical for cellular function → metabolism, replication ect.
how many chromosomes does a bacteria have
usually one circular dsDNA
Bacteria divide by ___ and in order to divide the chromosome must undergo ___
BINARY FISSION
SEMI-CONSERVATIVE REPLICATION
___ unzips the the dsDNA to allow ___ to fill in the second strand in both directions.
DNA Helicase
DNA polymerase
bacterial chromosomes have what special shape
SUPERCOILED circular dsDNA
what helps un-supercoil bacteria?
DNA Gyrase and Topoisomerase IV
what helps super coil bacteria
DNA gyrase
Two critical enzymes: ____ and ____ , are responsible for the coiling and uncoiling of bacterial DNA.
what type of drug attack DNA gyrase and topisomerase IV
fluoroquinolones such as Baytril(enrofloxaxin)
Many genetic determinants of ___ are not original pieces of a bacterial chromosome. They are acquired through ___
virulence and antimicrobial resistance
horizontal gene transfer
mobile genetic elements
___ is exchange of genetic information between bacterial cells
horizontal gene transfer
plasmid
self-replicating, self transmissible extra chromosomal element that undergoes conjugation to transfer from one bacteria to another
mini chromosome that bacteria pass to eachother during “sex”
bacterial ribosomes are made of Made up of 2 subunits (___) which are distinct from the mammalian ribosome.
30s and 50s
what type of antimicrobials target ribosomes
macrolides,
aminoglycosides,
tetracyclines
protein synthesis inhibitors (MCAT)
Highly conserved ___ gene is important for genetic identification of certain bacteria by DNA sequencing and population studies
16s rRNA
codes for ribsomes
Fimbriae vs flagellum
___ are used for motility
flagella
Some bacteria (___) have “periplasmic flagella” or an axial filament, which rotates and drives the entire cell forward.
spirochetes
moves like an inch worm
