Microbiology chapter 27 & 28
Eutrophication
An increase in nutrient levels that stimulates the growth of a limited number of organisms, thereby disturbing the ecology of these aquatic ecosystems.
Parasite
An organism that feeds on a living host
epibiotic predators
Attach to their prey organisms surface Ex. Attach to the outer membrane and secrete degradative enzymes that result in lysis and the release of the prey's cytoplasmic contents.
Mineralization
Describes the decomposition of organic matter to simpler, inorganic compounds (CO2, NH2, CH4, H2)
competitive exclusion principle
Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
dissimilatory nitrate reduction
When respired, the nitrogen is not incorporated into cellular material, so this is called _____________
dissimilatory sulfate reduction
When sulfate diffuses into anoxic habitats, it provides an opportunity for microbial ___________________
endosymbiont
a cell that lives within a host cell
Amensalism
a relationship in which one organism is harmed and the other is unaffected
Mutualist
a type of symbiosis in which both organisms or populations are benefited
Zooxanthellae
a yellowish-brown symbiotic dinoflagellate present in large numbers in the cytoplasm of many marine invertebrates.
Environmental microbiology
branch of microbiology studying the role of microorganisms in soils, water, and other habitats
biogeochemical cycling
cycling of nutrients from abiotic to biotic sources through biological, geological, and chemical processes.
greenhouse gases
gases in the atmosphere that trap energy
Simplified Nitrogen Cycle
(The goal is to get usable nitrogen from the air into the soil so it can be absorbed by plants and enter the food chain.)
Ectosymbiont
organism located on surface of another organism (usually larger)
genomic reduction
- outcome of long-term parasitic relationship -parasite loses unused genomic information
anammox reaction
-anaerobic reaction performed by chemolithotrophs -ammonium ion (NH4+) serves as the electron donor and nitrite (NO2-) as the terminal electron acceptor; it is reduced to nitrogen gas (N2) -shortcut to N2, proceeding directly from ammonium to nitrite, without having to cycle first through nitrate
The CO2 is carried to the endosymbionts in three ways:
1. Freely in bloodstream 2. Bound to hemoglobin 3. As organic acids such as Malays and succinate
Carbon cycle influenced by 4 other factors
1. Oxidation-reduction potential 2. Availability of competing nutrients 3. Abiotic conditions such as pH, temperature, O2, and osmotic conditions 4. The microbial community present
Symbiosis
A close relationship between two species that benefits at least one of the species.
The initial product of nitrogen fixation is
Ammonia
When organic molecules are mineralized they release nitrogen in the chemical form of ________
Ammonium
redox potential
A measure of the tendency of a given redox pair to donate or accept electrons.
coral bleaching
A phenomenon in which algae inside corals die, causing the corals to turn white. Loss of either the photosynthetic pigments from the zooxanthellae or the complete expulsion of the dinoflagellates from the coral.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
Parasitism
A relationship between two organisms of different species where one benefits and the other is harmed
assimilatory nitrate reduction
Can be reduced and incorporated into microbial and plant cell biomass in a process known as ___________
Comammox
Complete ammonia oxidation
Denitrification
Conversion of nitrates into nitrogen gas
Which molecules represent reduced forms of carbon?
Glucose, glycine, methane
interspecies hydrogen transfer
H2 production by one partner is linked to H2 consumption by the other
Endobiotic predators
Invade the victims cytoplasm or periplasm where they consume the contents to obtain the energy and precursors needed for cell division.
Biomagnification
Methylated Mercury forms are volatile and lipid soluble, and Mercury concentrations increase with each link of the food web in a process known as ________________
The conversion of gaseous nitrogen to its organic forms is referred to as
Nitrogen fixation
Mercury Cycle
Nowadays, human activities are the most important source of mercury to the environment. Because mercury is taken up by plants and animals and stored in their tissues, they play an important role in the cycling of mercury.
Immobilization
Nutrients converted into biomass become temporarily unavailable for nutrient cycling
How would the process by which organic matter is converted into carbon dioxide be described?
Oxidative
What kind of process is sulfur oxidation?
Oxidative
Coevolution
Process by which two species evolve in response to changes in each other
nitrogen fixation
Process of converting nitrogen gas into ammonia
What kind of process is denitrification?
Reductive
What kind of process is the conversion of Fe3+ to Fe2+ in anaerobic respiration?
Reductive
What kind of process is the conversion of sulfate to hydrogen sulfide?
Reductive
mycobiont
The fungal component of a lichen
Most useful distinction between cooperation and mutualism is
The observation that cooperating organisms can grow independently, although they may not function as well.
The carbon cycle
The organic circulation of carbon from the atmosphere into organisms and back again
symbiont
The smaller participant in a symbiotic relationship, living in or on the host.
Commensal
describes an organism that lives symbiotically with a host; this host neither benefits nor suffers from the association
Microbial Interactions
more than one kind of organism interacting with each other
Lichens
represent symbiotic relationships between a fungus and a photosynthetic partner
Ruminant stomach
rumen, reticulum, omasum, abomasum
Syntrophy
some bacteria live together and supply each other with essential nutrients
Bacteriocytes
specialized aphid cells
phycobiont
the algae component of a lichen
assimilatory sulfate reduction
the reduction of sulfate for use in amino acid and protein biosynthesis
Competition
the struggle between organisms to survive in a habitat with limited resources