ENV MICRO Flashcards
Symbiosis
Two taxonomically unrelated species exist in intimate association with another
- Mutualism
- Commensilism
- Parasitism
Mutualism
A relationship from which both partner species derive clear benefit…has two subtypes obligate and facultative
Commensilism
A relationship from which one symbiont benefits at neither cost nor benefit to the second symbiont
Parasitism
A relationship from which one species benefits at cost to individual host
is parasitism costly to host species?
No because it takes care of the weak and ultimately strengthens herd immunity
Facultative Mutualism
Humans harbor Staphylococcus species on skin epidermis. Humans benefit by gaining protection from pathogen. Symbiont gains place to live and derives nutrients from epithelial surface. May be any of several staphyloccocus species
Obligate Mutualism
Warm blooded animals harbor E coli as large intestinal indegnous flora. We get protection against pathogens and vitamin K, they get warmth, humidity and nutrients
Obligate Mutualism examples
- Leaf cutter ants & fungal gardens
- coral polyps & Anemones and zooxanthellae
- lichens
Commensilism
diptheroids may colonize conjunctive they gain protected environment at neither cost nor benefit to the colonized animal
Parasitism
an organism that cannot complete its life cycle without depending on a host in or on whose body it lives, and from whose tissues it derives metabolic support
-Viruses, Chlamydiae, Malaria, Toxoplasma gondii, and Diphyllobothrium latum
Biofilms
- Microbes exist in communities within which there is quorum sensing
- communication that enables the members of the community to coordinate activities even though they are unicellular organisms
- hydrogel which contains abundant water and polysaccharides, dna and proteins along with cells
- communities may include only one species or diverse organisms
Where do biofilms form and what can they do?
Bio films generally form on surfaces, plaque on teeth, filtering beds in sewage treatment plants, and indwelling medical devices
Organisms in biofilms do things individual cells would have a hard time doing on their own like in nutrient sharing, resistance to dessication and microbicides.
Ecological Roles of Microbes
Microorganisms occupy virtually all potential types of niches…Producers, Detritivores, and Predaceous consumers
Producers
Photoautotrophs: cyanobacteria, diatom, dinoflagellates
chemoautotrophs: many archaea
Detritivores
Organisms of decay in soils and water
i.e slime molds, water molds, true fungi and many bacteria
Predaceous consumers
Protozoans: Parmecium, Amoeba
Biogeochemical Cycles
- Global scale cycles of biologically important elements or small molecules
- these cycles exist for Carbon, Nitrogen, Phosphorus, and Sulfer, some other elements and food and water
- cycle feature passage of material being cycled through four major reservoirs
4 major reservoirs in biogeochemical cycles
- Atmosphere: air, including water vapor
- hydrosphere: liquid water on earth’s surface
- Lithosphere: solid, non living matter, crust, glaciers, etc
- Biosphere: living matter present in all ecosystems
Microorganisms in biogeochemical cycles
- microbes mediate many steps in various biogeochemical cycles
- the major biogeochemical cycles could not be completed without the presence and activities of microorganisms
-in nitrogen cycle, certain steps in cycle are only done by microbes
-Nitrogen fixation is only done by a limited
variety of bacterial gene
Carbon Cycle
Carbon fixation is the conversion of inorganic carbon usually as CO2 to organic carbon
- most commonly done by photosynthesis - done by plants and other photoautotrops such as diatoms and dinoflagellates
diatoms
most abundant marine producers
dinoflagellates
along with diatoms, these organisms are important as zooxanthellae symbionts of coral and anemones
