Microbiology exam 3 Flashcards
What do biogeochemical cycles do?
Biogeochemical cycles link metabolic processes of organisms for production and deflation of biomass.
What does it mean when all biomass consists of biogenic elements in roughly similar proportions?
Cycling of elements
What are the four types of reservoirs?
Terrestrial, aquatic, atmospheric, and living
What is the movement of elements between reservoirs (reaching equilibrium over the long term)?
Flux
What detects atmospheric gases?
When chemical cycling is monitored. Air will be collected in a sealed container is subjected to infrared radiation. If more is absorbed, more CO2 is present and will absorb the infrared radiation.
What method is used to monitor chemical changes over time (artificially enclosed ecosystems)?
Mesocosms
What method is used to monitor chemical changes over time that will label molecules with radioactive elements prior to release in a mesocosm?
radioisotope tracers
How do microbes influence the cycling of carbon? A balance is maintained between organic and inorganic carbon reservoirs.
global carbon cycle
What occurs when CO2 fixation exceeds respiration?
Organic matter will accumulate and create a positive net community productivity.
What is the production of methane as a byproduct of biodegradation of organic carbon in an anoxic environment?
Methanogenesis
What are syntrophic partnerships?
The relationship between the individuals of different species (especially of bacteria) in which one or both benefit nutritionally from the presence of the other.
What are archaea that produce methane as the end product, can only use specific substrates, and live in a community of microbes to utilize products from each other?
Methanogens
What does hydrogenotrophic methanogens produce CH4 from?
CO2 and H2
What does acetotrophic methanogens produce CH4 from?
acetate
What is the metabolism of CH4 into other forms which allows greater carbon cycling and occurs aerobically or anaerobically?
Methanotrophy
What are aerobic methods of methanotrophy dependent upon?
methane monooxygenase
What are anaerobic methods of methanotrophy dependent upon?
archaea (anaerobic methane oxidizers, ANMEs)
What are the three steps of the nitrogen cycle?
Notrogen fixation
nitrification
denitrification
What is the process that converts N2 into NH4+ by a nitrogenase complex and is carried out by aerobic/anaerobic bacteria and archaea?
nitrogen fixation
What is the process that converts NH4+ into nitrite (NO2-) or nitrate (NO3-)?
Nitrification
What enzymes produce nitrate?
ammonia monooxygenase and hydroxyl amine oxidoreductase
What enzyme produces nitrate with nitrifiers?
nitrite and nitrite oxidoreductase
What is the use of nitrate/nitrite as a terminal electron acceptor which eventually produces N2?
Dentridication
What process produces synthetic nitrogen fertilizer?
Haber-Bosch process
What are “dead zones”?
Overuse of fertilizers contribute to marine dead zones, imbalancing nitrogen reservoirs and ecosystems
What process actively cycles reservoirs of O2, CO2 and H2O, is cycled back and forth between photosynthesis and respiration reactions, and can be used marginally in anaerobic respiration using SO4(-2))?
Cycling of Oxygen
What process is usually found in rocks and dissolves in water, incorporation occurs through terrestrial and aquatic microorganism into higher-order organisms, and its decomposition reactions release the elements back into the terrestrial and aquatic systems?
Cycling of sulfur and phosphorus
What are abiotic and biotic interactions and exchanges of materials between organisms and their surrounding environment?
Ecosystems
What community of organisms capture energy through photosynthesis?
primary producers
What community of organisms ingest/utilize stored photosynthetic energy?
consumers
What community of organisms recycle components back into environments?
decoposers
What are function groups of members of communities and satisfies as a niche?
guild
What is the specific functional role of an organism within an ecosystem?
Niche
What are groups/layers of microbes on a surface that interact with an support each other?
Biofilms
any surface with water on it can form a biofilm for microbes
How does biofilm formation begin?
Appendaged bacteria form the primary layer on a surface and then secondary colonizers join the biofilm.
What do appendaged bacteria and secondary colonizers secrete?
Exopolysaccharide (EPS)
When microbes can be grown in the lab setting, they may grow slowly or may be rare in a mixed population. What method promotes the grown of desired microbes over undesired cells?
Enrichment cultures
What type of enrichment culture illustrates enrichment in action and displays how different microbes flourish in different areas of the column that correspond to different nutritional microenvironments?
Windogradsky column
What type of cultivation-independent technique is the extraction of DNA from an environmental sample and followed by PCR?
Direct sequencing
What type of cultivation-independent technique takes DNA from an environmental sample to construct a genomic library?
Metagenomics
What does “overfeeding” marine microbes leads to?
Anoxic water states (“dead zone” formation)
What are areas without enough oxygen to support much eukaryal life?
Dead zones
How are carbon and energy distributed through levels of marine ecosystems?
Zooplankton feeding on phytoplankton and through viral-mediated lysis
How does primary production occur in marine ecosystems?
phytoplankton
What marine ecosystem is when phytoplankton production drifts downward to feed zooplankton in the lower levels?
Dark mid-water zone
What marine ecosystem has an average seafloor depth of 3500 meters with the deepest spot being 11000 meters?
Deep-sea zone
What are microbes that can withstand intense pressures to grow?
Piezophiles
What kind of viruses are present in the ocean and liberate nutrients from cyanobacteria?
cyanobacteria viruses
What are categories of ecosystems based on vegetation characteristics?
Biomes
What are the dominant primary produces on land?
Plants
What is formed through microbial decomposition of plant and animal matter, combines with abiotic minerals and excreted nutrients from plant roots, and forms horizons based on physical type and characteristics?
Soils
What is the area of soil immediately surrounding plant roots that possess large amounts of organic carbon?
Rhizophere
What is the soil outside the rhizosphere that is not penetrated by plant roots
bulk soil
What are benefits that plants obtain from microbes
production of hormones
production of antibiotics
fixation of atmospheric nitrogen
solubilization of phosphate
What is the use of microbes to consume and remove human-made materials from soil?
Bioremediation
What are chemicals that are not normally found in nature?
Xenobiotics
What involves the addition of a nutrient that stimulates a broad substrate-range degradation pathway?
Cometabolism
What involves specific addition of a known degrading microbe to a contaminated environment?
Bioaugmentation
What type of symbiont occurs when one species does obvious harm to the other (pathogens)?
Parasitism
What type of symbiont occurs when one species benefits, but nothing happens to the other species (microbes on skin)?
Commensalism
What type of symbiont occurs when both species are getting some benefit from the arrangement?
Mutualism