Chapter 5 (Book) Flashcards
general result of Arrhenius eqution
growth rate doubles for every 10C rise in temp
high temp causes proteins to ________
denature
low temp causes a decrease in…
membrane fluidity and mobility of enzymes
psychrophilic protein adaptation
more flexibility and require less heat to function
downside is they denature at lower temps
psychrophilic lipid adaptation
more unsaturated FA so membrane is more fluid
downside is that at higher temp the membrane is too flexible and fails to maintain integrity
psychrophilic cryoprotectants
proteins like trehalose that depress the freezing point so they don’t freeze
thermophile adaptations
more H-bonding
chaperones that refold proteins after denaturation
DNA-binding proteins that stabilize DNA
enzymes to super supercoil DNA
thermophile membrane adaptations
saturated FA for more h-bonding
archaea do a monolayer
heat-shock response
activates stress response genes
make chaperones to maintain protein shape
enzymes change lipids in the memb.
many barophiles are ________
psychrophilic b/c temp at ocean floor is 2C
barophilic thermophiles exist in vents
barophilic adaptations
must maintain flexibility so many unsat FA
pressure-adapted ribosomes
bacteria in a hypertonic solution do what
import/synthesize compatible solutes - small molecules that don’t disrupt cell metabolism
attempt to balance the osmolarity
bacteria in hypotonic solutions
press-sensitive channels leak solutes out
why do halophiles keep a low intracellular Na+ concentration
solutes are moved into the cell by symport with Na
special pumps exchange Na out for K in
alkaliphile adaptations
sodium motive force (provides energy for flagella, symport)
use a Na+ out H+ in pump
H+ in drives ATP synthase
aerobic respiration
the use of O2 as the terminal electron acceptor
aerotolerant anaerobe
only uses fermentation for energy
possesses enzymes to deal with ROS
starvation activates _______ genes
survival
eutrophication
sudden infusion of a large amount of a formerly limiting nutrient
causes a bloom of microbes
threatens existence of some microbes
how do organisms that synthesize antibiotics avoid getting killed by their own antibiotics
the producing organism may lack the target molecule
if the antibiotic enters the organism, it modifies it
