Chapter 3 (Notes) Cell Interior 2 Flashcards
do prok internal structures usually differ from euk?
yes
prok not memb bound; have protein/protein-lipid memb
no DNA (like mitochondria/chloroplasts)
prok unique internal structures
membrane rich structures for energy generation
microcompartments
external features for motility and attachment
microcompartments
inclusions, vesicles, and storage granules
store specific molecules including gas
is cytoplasm viscous?
yes, affects diffusion rate
prok ~8nm^2/sec
Brownian motion
random, diffusive motion
features of photosynthetic bacteria
thylakoid memb
rubisco - fixes CO2
thylakoid membrane
where photosynthesis occurs in cyanobacteria
protein bound compartments contain Rubisco (a carboxylase)
chlorosome
photosynthesis in green sulfur bacteria occurs here
galactolipid monolayer
oxygenic
generating oxygen
inclusion body (storage granule)
stores excess compounds when prok are grown in high [ ]
sulfur, phosphate, carbon (in form of glycogen or PHA-polyhydroxyalkanoates)
endospore
differentiated cell formed in response to starvation
metabolically inert
functions of endospores
for survival
resistant to heat, desiccation, radiation, chemicals, and dyes
endospores are for ________, fungal spores are for _______
survival, dispersal
Bacillus thuringiensis produces what
a parasporal crystal (Bt-toxin) that is toxic to insects
the gene has been genetically engineered into plants so they dont have to depend on the bacteria
endospore forming bacteria are mostly found in the gram-___ phylum ________
gram-pos, Fermicutes
many are pathogenic
3 types of miscellaneous structures
protein-bound enterosomes
intracytoplasmic membranes
magnetosomes
protein-bound enterosomes
contain enzymes to metabolize compounds found in mammalian intestines
intracytoplasmic membranes
where NH4 oxidation occurs
Nitrosococcus oceani
magnetosomes
membrane encapsulated compartments filled with crystals of magnetite (Fe3O4)
allow bacteria to orient and migrate along magnetic field lines
motion due to flagella
may work with aerotactic capabilities so cell can locate appropriate oxic environment
magnetite (Fe3O4)
a naturally magnetic mineral
5 structures for attachment or adhesion
pili/fimbriae
sex pili
nanotubes
stalks
capsules
pili/fimbriae
straight filaments of pilin protein
sex pili
used in conjugation
nanotubes
intercellular connections that pass material from one cell to another
stalks
membrane-embedded extensions of cytoplasm
tips secrete adhesion factors called holdfasts
capsules
slime layers and glycocalyx made of polysaccharides or polypeptides
structure for movement?
flagella - uses ATP
4 types of flagella
peritrichous - all over
monotrichous
lophotrichous
amphitrichous
flagella structure
anchored to cell by filament, hook, and basal body
basal body has a motor that rotates the filament
made of the highly antigenic protein flagellin
do archaeal flagella differ from bacterial?
yes
different attachment to cell envelope
chemotaxis
the movement of a bacterium in response to chemical gradients
in chemotaxis, alternating…..
runs and tumbles cause a “random walk” that becomes biased toward an attractant or away from a repellant
tactic means…
movement
word before tactic describes how they move
gliding
movement that doesn’t use flagella
how does chemotaxis work
counterclockwise (CCW) rotation moves cell toward an attractant
clockwise (CW) rotation stops forward motion - causes tumbling and a change in direction
CCW toward attractant, CW tumble, random walk, swim toward attractant
