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86 Cards in this Set
- Front
- Back
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Symbiosis greek meaning
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Sym-Together - life-bios
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Types of symbiosis
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mutualism, parasitism, and commensalisms
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endosymbiosis
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microorganisms within host cells
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ectosymbiosis
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microbes attach but remain outside
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Mutualism and examples
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both orgs benefit from each other. Exs: Nitrogen fixation, lichen, mycorrhizae, flashlight fishes, symbionts of protozoa and insects, symbiosis in ruminants
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Rhizobium Nitrogen Fixation
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gram - heterotrophic soil bac called Rhizobia form symbiotic association with legume family
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Frankia (actinomycetes) nitrogen fixation
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symbiotic N fixation with non-leguminous plants ex. Alder (Alnus), california lilac (ceanothus), and Austrailian pine (casuarina)
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Nitrogen fixation of Anabaena
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forms symbiotic N fixation with Azolla (water fern)
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Nitrogenase does what process
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N(triple bond)N ---nitrogenase--->NH3
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What is nitrogenase made of?
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dinitrogenase and dinitrogenase reductase(contains Mo or molybdenum). both contain Fe. Cofactors called FeMo-co
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Nitrogenase destroyed by
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oxygen. in Rhizobia-legume symbiosis, leghemoglobin binds and removes oxygen from nitrogenase
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Nif gene
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20 genes, closely studied in K. pneumoniae, controlled by 7 operons. Code for Nitrogenase and nitrogenase reductase
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Detection (assaying) of nitrogenase activity
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reduction of HC≡CH (acetylene)
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Lichen are made of
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a fungi (mostly ascomycota) and algae or cyanobacteria. Fungi is protection. Algae makes food
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Lichens env
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colonizers of stressful habits. desert, Artic, and Antarctic. Rocks, trees, gravestones.
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Lichens are a food source to
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reindeer and caribou
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Lichens are sensitive to
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air pollution (Sulfur and N) making them natural indicators of air quality
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How quickly do lichens grow?
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1-2 mm/year - SLOW
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Mycorrhizae
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symbiosis btw fungi and plants. plants get minerals and fungi obtain carbs
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What are the two kinds of Mycorrhizae?
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Ectomycorrhizae and Endomycorrhizae
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Ectomycorrhizae
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woody plants (pine oak and birch). fungi forms sheath, called mantle around roots. hyphal network (hartig net) extend into root btw cells
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Endomycorrhizae
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80% of vascular plants. fungi penetrate into root cortical cells and form arbuscular in cortical cells
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Flashlight fish
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symbiotic relationship involves luminescent bac and fish (Anomalopidae). Light communicates, lures prey, and confuses predators
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Symbionts of Protozoa
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bac are highly host specific (depend on one or two host genes). Common host are paramecium aurelia and amoebas. help with cellulose digestion.
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Symbionts in insects
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endosymbionts. help with cellulose digestion in cockroaches and termites
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Symbionts in Ruminants
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decompose cellulose and plant materials. provide protein and vitamins for ruminents. rumen provides good env for bac growth
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What animals have ruminents?
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cows, goats, girraffes, camels and sheep
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parasitism
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parasite benfits by growth and reproduction. host is harmed. ex of parasites - viruses, bac, protozoa, and fungi
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potatoe blight
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cause great irish famine (1845-1849) 1 mill died = 12% pop. Oomycota - Phytophthora infestans
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Malaria
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caused by protozoan (plasmodium). kills a Lot!! especially young
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Why are chlamydiae obligate intracellular pathogens?
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bc they cannot make their own high-NRG cmps, rely on host metabolism
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bdellovibrio
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curved gram - that preys on gram - by boring into cell wall and dividing in periplasm.
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commensalisms
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symbiotic relationship. one benefits other is unaffected. ex. mircoflora
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What are dynamic relationships?
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mutualism, parasitism, and commensalism can all change depending on enviroment. Ex. antibiotics, immune system impaired
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How many microbes on a human?
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10^13 human cells. 10^14 bac
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Antagonism
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normal flora protects their territory against other bac (some potentially harmful)
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lactobacilli antagonism
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inhibit vagina and keep Candida population low
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C. difficile
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low numbers will increase when antibiotics given. result is PMC 0 pseudomembranous colitis, fever, cramps, diarrhea.
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Synergism
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some bac grow better together
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Syngerism example
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Enterococcus fecalis (makes phenyalanine) and Lactobacillus arabinous (folic acid)
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Reservoirs
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where infectious microbes can be found
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Inanimate reservoirs
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Soil - anthrax spores. Water - fecal coliforms. Food - E. coli
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Animate reservoirs, stages
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1. healthy, 2. incubatory - infected w/o symptoms. 3. convalescent - recovered from disease, still shed agent
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Direct disease transmission
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pathogens are transmitted directly. human to human or animal to human
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Indirect disease transmission
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transmitted via fomites of vectors
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Portals of entry
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nose, mouth, eyes ears, genitourinary tract, and cuts
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sequence of infectious disease
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iPADC. incubation, then clinical illness: prodomal period (first symptoms), acute (peak), decline, convalescent period (recovers)
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Latent infections
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disease that don't immediately produce symptoms. Ex - herpes simplex virus
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Most pathogens invade a specific_____
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tissue or organ
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Shigella dysenteriae
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GI tract
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Brucella
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grows in placenta, needs erythritol (4 C alcohol)
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N. gonorrhoeae
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possess pili to attach to urogenital mucosal cells
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Hemolysins
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streptococcuse pyogenes makes. to destroy RBC's
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Streptolysin O
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hemolysin. O2 sensitive. inactivated by oxygen. attacks RBC and WBC
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Streptolysin S
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oxygen stable hemolysin. attacks RBC
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Streptokinase
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protease that converts plasmogen in human serum to plasmin (dissolves blood clots causing disease to spread)
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Capsules protect bac from
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phagocytosis
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Bacteria that use capsules
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S, K pneumoniae, N. meningitidis, B. anthracis
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Exotoxin
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soluble protein released into the surrounding env during bac growth and metabolism
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Endotoxins
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lipopolysaccharide portion of membrane. Lipid A is the toxic part of LPS molecule. released at bac death
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Enterotoxins
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impact small intestine. ex. S. aureus
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Neurotoxins
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affect nerve tissue
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Cytotoxins
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impact all cells
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Neurotoxin Botulism
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1 mg could kill 1,000 ppl. blocks release of acetylcholine
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Cytotoxin in Diphertheira
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disrupts protein synthesis
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Toxoids
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exotoxins that are converted by formaldehyde. not toxic but produce immune response
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Pyrogens
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cause fever. leukocyte response to endotoxins
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Lysozyme
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antimicrobial in nasal secretions, saliva and tears. Hydrolyzes peptidoglycan
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Interon
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antiviral agent
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Three parts of blood
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Plasma and Serum (cellular portion and fluid portion)
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Three major cellular components
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erythrocytes, platelets, and leukocytes
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Erthrocytes
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RBC. hemoglobin to transport O2 and CO2
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Platelets
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thrombocytes. transport of serotonin. clotting
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leukocytes
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WBC. 5 types
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5 types of leukocytes
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Granulocytes: BEN Agranulocytes: L and M. Basophil, eosinophils, neutrophils, lymphocytes, monocytes
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Basophils
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contain vasodilator histamine. released during hypersensitive reactions
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Eosinophils
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phagocytotize Ag-Ab complexes
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Neutrophils
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PMN. play a role in phagocytosis
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Lymphocytes
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T and B cells. cell mediated immunity. antibody production
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Monocytes
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active in phagocytosis
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Reticuloendothelial system
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wandering macrophages and stationary macrephages
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What the two primary defenses of the body?
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reticuloendotheial system and lymphatic sytem
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Lymphatic system
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collects excess fluid (lymph). flows through small structures (lymph nodes) that contain lymphocytes and macrophytes to clear the lymph of pathogens
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inflammation
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dilation and increased permeability of blood vessels - producing edema, erythema, pain and heat
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Inflammation is in response to what?
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injury, infection, and irritation
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phagocytosis
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chemotactic marking, phagocyte attaches, opsonins (form bridge), pseudopods around object. becomes phagolysosome
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