Chapter 3 (Book) Part II Flashcards
sacculus
another name for bacterial cell wall
cage-like structure that is porous to ions and organic molecules
is the cell wall a single molecule?
yes, envelops the cell
does the cell wall determine the cell’s shape?
no, it is flexible
shape depends on proteins in the cytoskeleton
murein
“wall molecule”
peptidoglycan - polymer of peptide-linked amino sugars
_________ is the target of penicillin
transpeptidase - enzyme that cross-links peptidoglycan
beta-lactamase
found is antibiotic resistant bacteria
cleaves the lactam ring of penicillin, rendering it ineffective
gram positive
thick cell wall with 3-20 layers of peptidoglycan
teichoic acids reinforce the peptidoglycan
gram negative
thin cell wall with 1-2 layers of peptidoglycan
enclosed by an outer membrane
capsule
slippery capsule of polysacchairde
mostly gram pos, some gram neg
s-layer (surface layer)
additional protective crystalline layer of protein or glycoprotein
has pore that let molecules through
mycobacterial cell envelopes
have weird membrane lipids called mycolic acids
hydrophobic waxy surface deters antibiotics and phagocytosis
mycobacterial cell wall
peptidoglycan linked to galactose
purpose of gram negative outer membrane
defensive abilities and toxigenic properties
gram negative layers
outer membrane
periplasm - where peptidoglycan is
inner membrane (cell membrane)
inner leaflet of outer membrane
phospholipid composition like a cell membrane
murein lipoprotein/Braun lipoprotein connects outer memb. to cell wall
if mutation in murein lipoprotein, can’t attach to cell wall so the outer memb. balloons out where the daughter cells separate
outer leaflet of outer membrane
lipopolysaccharide (LPS) with shorter FA chains
LPS acts as an endotoxin
endotoxin
a harmless substance that is released when lysed
causes endotoxic shock
outer membrane proteins
porin transporters that permit the entry of nutrients like sugars and proteins
periplasm
found btw inner and outer memb.
has enzymes and nutrient transporters for aa, sugar, or nutrients
4 cellular compartments of a gram neg
outer memb, periplasm, inner memb. cytoplasm
contractile vacuole
a pump that prevents osmotic shock in eukaryotes without a cell wall
3 bacterial cytoskeleton proteins
FtsZ
MreB
CreS
FtsZ
forms a Z-ring in spherical bacteria (cocci)
in rods, determines cell diameter
MreB
helical coil in rod shaped bacteria that elongates it
CreS
cresentin found in curved bacteria
DNA is organized in the ________ region
nucleoid
in loops called domains
origin of replication
where DNA polymerase starts synthesis bidirectionally
rifampin blocks…
RNA synthesis
tetracycline blocks….
tRNA by binding 30S subunit
erythromycin blocks…
peptide elongation by binding 50S subunit
polysome
a polyribosome
mRNA with multiple ribosomes attached
transertion
coupling of transcription and translation to membrane insertion
uses a signal recognition particle
cell division is called
fission
is DNA replicated bidirectionally?
yes
replisome
complex of DNA polymerase with accessory proteins
replicates leading and lagging strands
________ completes cell division
septation - grows inward from the sides of the cell and constricts off the 2 daughter cells
what triggers growth of the septum (dividing partition of the envelope)
replication of the DNA termination site
spatial orientation of septation has a key role in determining the shape and arrangement of _____
cocci
spatial orientations of septation
parallel planes - streptococci chains
random - staphylococci
right angles - tetrads or sarcinae
in rod shaped cells, cell division requires the envelope to ________ before septation
elongate
cell expansion and septation are coordinated with ____ ________
DNA replication
polar aging
in rod shaped bacteria, the poles differ in age
thylakoid
in photosynthetic bacteria
extra folded intracellular membrane with rubisco
gas vesicel
in aquatic and marine phototrophs
increases buoyancy
during times of starvation, phototrophs may digest their _________ for energy and as a source of nitrogen
thylakoids
sulfur storage granule
used to store sulfur
magnetosome
membrane embedded crystals of magnetite, a magnetic mineral
can align along a magnetic field
magnetic bacteria are anaerobes
they can move toward magnetic north where there is less oxygen
pili/fimbriae
adherence structure made of the protein pilin
sex pili
attach a male donor to a female recipient in conjugation
stalk
attachment structure of extended cytoplasm
tip secretes holdfast adhesion factors
nanotubes
extensions of cell envelope that connect cytoplasm/periplasm between 2 different cells for nutrient transfer
motility
the ability to move and rotate
flagella
helical propellers that drive the cell forward
spiral filament of flagellin
basal body is the motor embedded in cell envelope…requires energy
chemotaxis
movement driven by a chemical gradient
CCW and CW tumbles and random walk
