Biology 44 Unit 2: Quiz 1
obliate anaerobe
O2 is toxic.
how can bacteria survive harsh periods?
entering dormancy
bacteria shapes
spheres (cocci), rods (bacilli), and spirals
water cycle
?
oxygen cycle
Bacteria produced the first oxygen and continue to generate through photosynthesis/ decomposition.
advantages and disadvantages of asexual reproduction
advantages: disadvantages:
How do bacteria breathe?
aerobe (use O2) vs. anaerobe (don't use O2).
how do bacteria get food and energy?
autotrophs make molecules from inorganic carbon heterotrophs use existing organic carbon
carbon cycle
bacteria are producers and decomposers of organic carbon.
nitrogen cycle
bacteria fix atmospheric nitrogen into usable ammonia.
endosphere
bacteria form tough endospore coats around DNA, protecting until conditions improve. (e.g. anthrax)
phosphorous cycle
bacteria mineralize soil phosphorus into usable form.
mutualistic symbiosis
both organisms benefit. ex. mussels use bacterial "fuel cells" to harness energy from hydrogen spewing out of hydrothermal vents. ex. angler fish has bioluminescent bacteria that live symbiotically in its long"lure" to attracts prey.
microorganism
can only be seen with a microscope (archaea and bacteria are examples).
biosphere
carbon cycle phosphorous cycle nitrogen cycle water cycle oxygen cycle
industrial applications of mutualistic symbiosis
cheese making, insulin production, oil spill cleanup
akinetes
cyanobacteria form food-filled akinetes to survive winter
aerotolerant anaerobe
don't use O2, but it won't kill them.
anatomy of a prokaryote
flagella, pili, cytoplasm, ribosomes, nucleoid region, plasma membrane, cell wall
bacteria cell walls
gram positive and gram negative
proteobacteria
many rhizobacteria, including those found in legumes (n-fixation). many disease-causing bacteria, such as vibrio cholere (cholera).
quorum sensing
microbes secrete molecules that influence neighbors, resulting in collective behavior. some bacteria aggregate together as biofilms.
bacteria
more diverse, more moderate habitats, and more interactions with other organisms. important bacteria: cyanobacteria & proteobacteria.
archaea
most notable members are extremophiles, capable of surviving extreme environments (hydrothermal vents, salt flats, hot springs). cell membrane with ether linkages allows some Archaea to survive extreme environments. some have a lipid monolayer.
facultative obligate
need O2 to live.
cyanobacteria
photosynthetic, responsible for early oxygen production. cause toxic algal blooms but also potential for carbon remediation.
parasitic symbiosis
one organism benefits, one is harmed
horizontal gene transfer
organism receives genetic material from another organism without being offspring. bacteria can exchange genetic material without reproducing.
prokaryotes
originated 3.5 mya, the first life forms
binary fission
single parent cell splits into two daughter cells with identical DNA. asexual reproduction (bacteria).
What makes a species successful?
takes in energy, produces offspring, avoids predators, survives environment, has not gone extinct
gram-positive
thick peptidoglycan layer, no outer envelope. more susceptible to penicillin
gram-negative
thinner peptidoglycan layer with outer envelope. more resistant to antibiotics.
human microbiome
trillions of bacteria species live symbiotically on human skin or inside organs. mutualistic symbiosis.
symbiosis
two organisms living in close association
pathogen
type of parasite that also causes disease symptoms (ex. tuberculosis, pneumonia, plague, tooth decay, etc.)
facultative aerobe
use O2 but can live without it.
chemoautotroph
use inorganic N, H, S, etc. to make energy and organic molecules. deep-sea vents.
photoheterotroph
use light for energy but need additional carbon. almost exclusively bacteria.
chemoheterotroph
use light for energy but need additional carbon. most species on the planet.
photoautotroph
use light to make energy and organic molecules. most species on the planet.