Exam 1- characterization of bacteria Flashcards
what is morphology characterization?
cell shape, arrangement, staining, pigments, and spores
What is metabolism characterization?
carbon and nitrogen sources, energy source, byproducts, and ABO sensitivity
What is habitat characterization?
Temperature, pH, osmotic pressure, oxygen tolerance, atmospheric pressure
what is molecular characterization?
how much guanine and cytosine content is present, and 16s RNA-stays stable overtime
what is taxonomy?
how was characterize organisms individually
what is nomenclature?
naming organisms
what is binomial nomenclature?
(Genus, Species,-italicized or underlined) (stain -0157:H7)
3 domains of life:
Eukarya- animals, fungi, plants
bacteria- bacteria, chloroplasts, mitochondrion
archaea -methanogens, hyperthermophiles
taxonomy:
Domain, kingdom, phylum, class, order, family, genus, species
diplococci
2 cocci
streptococci
string of many cocci
tetrad
4 cocci
sarcinae
cube of 8 cocci
staphlococci
cluster of many cocci
diplobacilli
2 bacilli
streptobacilli
string of many bacilli
coccobacillus
irregular shaped cocci/bacilli
vibrio
1/2 spiral
spirillum
corkscrew spiral
spirochete
tight/thin spiral
filamentous
long thin cell
what cells do not have a phospholipid bilayer?
archea
what does a phospholipid bilayer consist of?
2 fatty acids
1 phosphate
glycerol (3- carbon chain)
what is the purpose of a phospholipid bilayer?
to separate two environments, a barrier
gram positive characterization:
inner membrane, thick peptidoglycan
gram negative characterization:
inner and outer membrane, lipopolysaccharide + protein, periplasm surrounding the small cell wall; peptidoglycan
why are spores produced in bacteria?
for dormancy-resist pH, temperatures, and radiation
vegetative cell:
actively dividing and metabolising
sporulating cell
forming a spore in the cell
mature spore
spore is released (dna is in the spore), rest of cell degenerates
germination
when a mature spore decides it’s time to divide and go back to a vegetative cell
sporulation
when an environment is suboptible-temp, pH, high salt, radiation, a cell produced spores to withstand it and become dormant
what triggers sporulation?
population density
sporulation efficiency
10-40% of cells produce spores
types of spore position:
central, terminal, subterminal (dictated by DNA/genetics)
types of spore shape:
round, oval (specific to species)
types of cell swelling:
cell swells around the spores, non-swelling spore (specific to species)
how does sporulation occur?
- DNA replication -central, terminal, or subterminal
- septum -plasma membrane created a barrier
- spore septum -forespore is formed, 2 membranes
- cortex -peptidoglycan layers form between membranes
- Dipicolinic acid (DPA) and calcium -accumulated inside endospore while cortex finishes forming
- SASP -DNA binding protein covers chromosome while DNA is being dehydrated by ca.DPA
- spore coat -made of keratin like structure is formed on outside of the spore to protect it
- spouting call’s DNA, cell wall, and call -denigrate
- endospore -is related from th cell creating a mature spore
what does DPA do for the spore?
interacts with the water and makes it unavailable so the DNA cannot interact with water and won’t be so sensitive to changing/drastic environments
What does SASP do for the spore?
protects the DNA from radiation
exosporial is what?
sometimes another coat formed around the endospore
how does germination occur?
- pore -communicates with the environment and when its stable for growth pore rehydration occurs:
if the spore decides, the genes in DNA allow water to flood into the call
then setting off a series of events - vegetative cell -ready for sporulation is created
is sporulation and germination reversible?
no
how long does vegetative cell-spore (sporulation) take?
6-8 hours
how long does spore-vegetative cell (germination) take?
1-2 hours
what is a glycocalyx?
sticky usually carbohydrate matrix on nearly all bacteria
-repeating units of carbohydrates or amino acids
purpose of a glycocalyx?
-protection against dehydration, chemicals, and viruses
-attachment -motility
what is a bacteriophage?
bacteria eating viruses
what diagnostic tool us sued to identify a specific organism by species or strain of glycocalyx?
K-antigen -the structure of the glycocalyx
what types of glycocalyx are there?
1.capsule
2.slime -gliding motility
what is the most common form of movement for bacterial cells?
flagella-flagellum
single polar flagellum:
monotrichous
many flagella on one polar end of the cell driving it in one direction:
lophotrichous
flagella on both polar ends of the cell
amphitrichous
multiple flagella not restricted to ends/poles (not polar)
peritrichous
do prokaryotic flagellum have cilia
no
What is an h-antigen?
sequence of flagellin-diagnostic tool
what is the arrangement of eukaryotic flagellum?
9+2 microtubule arrangment
what is trichous movement also considered?
run and tumble
what is false motility or Brownian movement?
shaking of the cell due to the water molecules “false motility”
what is chemotaxis?
movement trades nutrients or away from toxins
what is ameboid movement?
no cell wall (macrophages) the flow of cytoplasm as extensions of the organism.
what is cytoskeletal propulsion?
(listeria, shigella, rickettsia) causes action to polymerize/pushes/infects cells, antibodies cannot defend against this
what is the use of endoflagellum?
Endoflagella are bundles of flagella called axial filaments that wrap around the cell body of spirochetes. The axial filaments cause the bundles of flagella to rotate to help the spirochete move in a twisting motion.
what do fimbriae do?
attachment, role in virulence, colonization-residency
what do pili do?
attachment, injection of toxins, F pilus-fertility
