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125 Cards in this Set
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how are prokaryotes different from eukaryotes?
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Prokaryotes: DNA has no nucleus, not wrapped around histones, circular shaped, have bacteria w/ peptidoglycan, no complex membrane bound organelles, archae-tough and made of other chemicals- distinct to them
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examples of endospores?
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bacillus, clostridium
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fimbriae
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fine harlike bristles extending from cell surface that help in ADHESION to another cell/ surface (Hairs)
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inclusion/ granule
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stored nutrients such as fat, phosphate, or glycogen deposited in dense crystals or particles that can be tapped into when needed (Big red circle looks like RBC)
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cell wall
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semirigid casing that provides structural support and shape for the cell (3rd layer from outside)
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cell (cytoplasmic) membrane
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thin sheet of lipid and protein that surrounds the cytoplasm and controls the flow of materials into and out of the cell pool. (innermost layer)
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outer membrane
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extra membrane similar to cell membrane but also containing lipopolysaccharide. controls flow of materials, and portions of it are toxic to mammals when released. (second layer from outside)
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endospore
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dormant body formed within some bacteria that allows for their survival in adverse conditions
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cytoplasm
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water based solution filling the entire cell (filler)
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flagellum
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specialized appendage attached to the cell by a basal body that holds a long, rotating filament. the movement pushes the cell forward and provides motility. (the tail)
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actin cytoskeleton
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long fibers of proteins that encircle the cell just inside the cell membrane and contribute to the shape of the cell. (looks like ribs)
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ribosomes
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tiny particles composed of protein and RNA that are the sites of protein synthesis (little beans)
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plasmid
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double stranded DNA circle containing extra genes. (circular hula hoop)
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pilus
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an elongate, hollow appendage used in transfers of DNA to other cells. (transport tube)
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bacterial chromosome or nucleoid
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composed of condensed DNA molecules. DNA directs all genetics and heredity of the cell and codes for all proteins.(spaghetti)
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glycocalyx
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pink coating/ layer of molecules external to the cell wall. it serves protective, adhesive, and receptor functions. it may fit tightly or be very loose and diffuse. (most external layer)
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what are appendages
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cell extensions; common but not present on all species. can provide motility (flagella and axial filaments), can be used for attachment and mating (pili and fimbrae)
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flagella
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three parts: filament, hook(sheath), and basal body. vary in number and arrangement.
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pili
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elongate, rigid tubular structure made of protein pilin. found on gram NEG bacteria, used in conjugation. (passing plasmid from one bacteria to another)
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glycocalyx
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develops as a coating of repeating polysaccharide units, protein, or both. sometimes helps cell adhere. differ among bacteria in thickness, organization, and chemical composition. - slime layer- loose shield that protects some bacteria from loss of water and nutrients
-capsule- when the glycocalyx is bound more tightly to the cell and is denser and thicker |
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what break down peptidoglycan?
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penicillins
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gram negative vs gram positive: which has thicker peptidoglycan layer?
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gram positive
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what are archaea
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unusual nontypical cell wall- chemically distinct
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mycoplasmas are?
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atypical cell wall (lack cell wall entirely) ex. PNEUMONIA. mycoplasma membrane is stablilized by sterols and is resistant to lysis. -very small bacteria, range in shape from filamentous to coccus, not obligate parasites, can be grown on artificial media, found in many habitats.
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obligate parasites
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cannot live without host (viruses)
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contents of cell cytoplasm
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gelatinous solution, site for many biochemical and synthetic activities, 70-80% H2O, contains larger, discrete cell masses (chromatin body, ribosomes, granules, and actin strands), no cell organelles
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bacterial chromosome
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single circular strand of DNA, aggregated in a dense area of the cell ( the nucleoid)
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plasmids
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nonessential double stranded circles of DNA, present in cytoplasm but may become incorporated into the chromosomal DNA, often confer protective traits such as drug resistance or the production of toxins and enzymes, NOT all bacteria have these
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ribosomes
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made of RNA and protein, special type of RNA- ribosomal RNA (rRNA), characterized by S (for Svedberg) units- the prokaryotic ribosome is 70S
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inclusions
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AKA inclusion bodies. some bacteria lay down nutrients in these inclusions during periods of nutrient abundance. serve as STOREHOUSE when nutrients become depleted. some enclose condensed, energy rich organic substances. some aquatic bacterial inclusions include gas vesicles to provide buoyancy and flotation
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actin cytoskeleton
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long polymers of ACTIN, arranged in helical ribbons around the cell just under the cell membrane, contribute to cell shape (treptonema pallidom- syphillus <S> shape b/c of actin cytoskeleton
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bacterial endospores
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dormant bodies produced by bacillus clostridium and sporosarcina
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phase 2: endospore
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stimulus for sporulation- the depletion of nutrients. vegetative cell undergoes a conversion to a sporangium. sproanguim transforms into endospore. hardiest of all life forms- withstands extremes in heat, drying, freezing, radiation, chemicals. heat resistance- high content of CA and dipicolinic acid. *some viable endospores have been found that were more than 250 million years old.
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germination- breaking of dormancy in the presence of h2o and specific germination agent. quite rapid *1.5hrs* . the agent stimulates formation of hydrolytic enzymes, digest the cortex, expose the core to h2o. medical significance- several bacterial pathogens... bacillus anthracis, blostridium tetani, clostridium perfingens (gangreen), clostridium botulinum. *resists ordinary cleaning methods
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three general shapes of bacteria
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coccus- roughly spherical
bacillus- rod shaped... coccobacillus is short and plump, vibrio is gently curved ex. Cholera (C shaped bacteria) spirillum- curviform ro spiral shaped ex. syphillus (treptonema pallidum) (S) shape pleomorphism- when cells of a single species vary to some extent in shape and size. *staph- grapes *strepto strands of cocci |
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grouping of bacteria
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cocci- greatest variety. single, pairs (diplococci), tetrads, irregular clusters (staph and micrococci), chains (strep), cubical packet (sarcina)
bacilli- less varied. single, pairs (diplobacilli), chain (strep), row of cells side by side (palisades) spirilla- occasionally found in short chains. |
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obligate intracellular parasites
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-rickettsias. very tiny, gram NEG, atypical in lifestyle and other adaptions, CANT survive or multiply outside a host cell, CANT carry out metabolism completely on their own.
-human diseases- rockymountain spotted fever by rickettsia rickettsii, endemic typhus by rickettsia typhi |
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chlamydias
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genera chalmydia et chalmydophila. require host cells for growth and metabolism. not closely related. not transmitted by arthropods. human diseases- chlamydia trachomatis- causes severe eye infection and the chlamidial STD. Chlamydophila pneumonia- lung infections
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lipopolysaccarides can cause
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septic shock or other kinds of shock (gram NEG)
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binary fission
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cell division in prokaryotic cells
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mitosis
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cell division in eukaryotic cells
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RC- rickettsia chlamydias
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REQUIRE CELL
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bacteria- cell type, type of ribosomes, presence of peptidoglycogen?
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prokaryotic, 70S, HAS peptidoglycogen
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archaea-cell type, type of ribosomes, presence of peptidoglycogen?
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prokaryotic, 70S but similar to 80S, LACKS peptidoglycogen
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eukaryotes: cell type, type of ribosomes, presence of peptidoglycogen?
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eukaryotic, 80S, LACKS peptidoglycogen
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examples of eukaryotes
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yeast, protozoa, algae, helminths, animal cells. external and internal structures more complex than prokaryotes
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flagellum of eukaryotes
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arranged in 9x2 fashion
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internal structures of eukaryotes
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nucleus, ER, golgi apparatus, mitochondria, chloroplast (photosynthetic cells), ribosomes, cytoskeleton
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nucleus
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membrane bound organelle. not found in prokaryotic cells, chromatin- chromosomal DNA, nucleoulus- site for RNA synthesis, histones- proteins that associate with DNA during mitosis
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rough ER
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coated w ribosomes, site of protein synthesis, transport material from nucleus to cytoplasm and cell membrane, transitional vesicles
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golgi apparatus
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closely associated with the ER, site for protein modification, cisternae- noncontinuous membrane network, condensing vesicles
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mitochondria
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powerhouse of cell
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ribosomes
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associated w protein synthesis, present in cytoplasm and surface of ER, 80S in RER, 70S ribosomes in mitochondria and chloroplasts
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microfilaments
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allow movement of molecules in cytoplasm
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microtubules
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maintain shape of cell and enable movement of molecules in cell
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fungi
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molds are filamentous fungi. the fungal thallus consists of hyphae; a mass a hyphae is a mycelium. yeasts are UNIcellular. Dimorphic fungi: mold-like at low temp, yeast at about *37C*
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malassezia furfur
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infection: tinea versicolor. tissue: outer epidermis
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candida albicans
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infection: candiadiasis or yeast. Tissue: mucous membranes, skin, nails
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coccidioides immitis dermatidtidis
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infection: coccidioidomycosis (san joaquin valley fever) tissue: lung
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blastomyces
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infection: north american blastomycosis (chicago disease). tissue:lung
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histoplasma capsulatum
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infection: histoplasmosis (ohio valley fever). tissue: lung
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cryptococcosis neoformans
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infection: cryptococcosis (torulosis). tissue:lung
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protista (protists)
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algae and protozoa. unicellular or colonial organism that lacks true tissues.
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algae
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photosynthetic, inhabitants of fresh and marine waters. most are not considered human pathogens. unique morphology enables identification
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pathogens
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produce toxins ex. red tide- months ending with "R" (shellfish)
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protozoa
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complex structure and function. -ectoplasm and endoplasm, - pseudopods, flagella, cilia.
inhabitants of fresh water and soil- heterotrophs. reproduction- (asexual). |
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trophozoite
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active (feeding) part of protozoa
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encystment
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The process of forming or becoming enclosed in a cyst
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malaria
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plasmodium vivax
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trichomonas vanginalis
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uses undulating membrane to propel- kind of like a fin
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life cycle of protozoa
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trophozite(active feeding), drying lack of nutrients, cell rounding early cyst wall formation, mature cyst(dormant resting stage), moisture and nutrients are given, cyst wall breaks open, trophozite is reactivated
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what is the kissing bug and associated disease?
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reduviid bug, carries infective trypanosome, chagas disease. potentially life threatening. can be spread in human dwellings or in wild by the bug. can take 20 years to develop heart or digestive problems. tx with ABX. occurs in poverty, living in a hut with the bug in the walls, or central/ south america
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helminths
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tapeworms, flukes, roundworms, unique structural morphology enables identification. organ like systems.
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how do you know if your child has pinworm?
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usually itching occurring at night. seen by putting scotch tape on anus. spread easily among kids. easily cured.
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ascaris lumbricoides
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common name: ascariasis. lives in humans. spread by: fecal pollution of soil with eggs
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enterobius vermicularis
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common name: pinworm, lives in humans. spread by: close contact
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trichinella spiralis
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common name: trichina worm. lives in pigs, wild animals. Spread by: consumption of meat containing larvae burrowing of larva into tissue
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taenia solium
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common name: pork tapeworm. lives in humans and swine. spread by: consumption of undercooked or raw pork
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diphyllobothrium latum
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common name: fish tapeworm. lives in humans and fish. spread by: consumption of undercooked or raw fish
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2 major structures of viruses
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naked nucleocapsid virus, enveloped virus
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capsid
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protective outer shell that surrounds viral nucleic acid
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capsid spikes
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attach to receptors to gain entry to cell
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capsid composed of capsomer subunits which do what?
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protect virus
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two types of capsids
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helical and icosahedral
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helical capsid
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NAKED Helical Virus: ex. tabacco mosaic virus. nucleocapsid is rigid and tightly wound into a cylinder shaped pkg.
ENVELOPED Helical Virus: ex. INFLUENZA, measles, rabies. nucleocapsid is more flexible. -helical capsids resemble a bracelet |
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envelope
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lipids and proteins. has envelope spikes. during release of animal viruses a part of the host membrane is taken. enable pleomorphic shape of virus- spherical and filamentous
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function of capsid/ envelope
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protect nucleic acid from the hosts acid and protein digesting enzymes. assists in binding and penetrating host cell. stimulates hosts immune sys.
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complex viruses
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structure is more intricate than helical and icosahedral viruses. pox virus- several layers of lipoproteins, coarse surface fibrils.
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bacteriophage
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virus that infects bacteria. polyhedral head, helical tail, fibers for attatchment
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nucleic acid
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viruses either contain DNA or RNA. possess only the genes to invade and regulate the metabolic activity of host cells. EX. HEP B and HERPESVIRUS. no viral metabolic genes, as the virus uses the hosts metabolic resources.
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sequence of multiplication
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adsorption, penetration, uncoating, synthesis, assembly, release
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cytopathic effects
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damage to host cell due to a viral infection. inclusion bodies EX>cytomegalovirus. synctia, chronic latent state, transformation... ends up with multiple nuclei
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bacteriophage
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bacterial virus. multiplication is similar to animal viruses except for the penetration (inject DNA), release (lyses), and prophage (lysogeny) stages.
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lysogeny
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when bacteriophage can insert its DNA into the bacterial host genome
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non cellular infectious agents
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prions, satellite viruses (delta agents), viroids
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prions
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protein particle w no nucleic acid, no envelope, no capsid. diseases: creutzfeldt-jakob (neurological), mad cow disease, scrappie. results in spongiform encephalitis and can take years to show signs. (KURU TRIBE) eating brains.
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satellite viruses
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dependent on other viruses for replication. EX: delta agent which is only expressed in the presence of Hep B virus
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Viroids
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plant pathogens- tomatoes, potatoes, cucumber. 1/10th of the size of a normal virus. naked strands of DNA, no capsid.
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what are plant viruses caused by
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VIROIDS, not prions!
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what stain shows capsules?
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negative
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conjugation
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transfer of genetic material
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what causes malaria?
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plasmodium parasite
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bacteria that lacks cell wall?
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mycoplasmas
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tapeworms are...
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cystodes
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a virus is an...
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obligate intracellular parasite
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orthomyxo (influenza) virus are segmented which means
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they can change
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virus that can cause oncogenic conditions?
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cancer, Epstein- Barr virus "Mono"
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characteristics of gram POS
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purple. 2 layers. large peptidoglycan. techoic acid. lipotechoic acid. no capsule/slime
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characteristics of gram NEG
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pink/red stain. LPS (lipopolysaccharides) which can cause septic shock. 3 layers. capsule/ slime layer. thin peptidoglycan layer
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Mycobacterium
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TB
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mycoplasmas are not obligate parasites which means...
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they can pretty much grow anywhere
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diptheria s/sx
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black lining in throat
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hibernating bacteria
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endospores
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what produce endospores
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bacillus, clostridium, sporosarcina
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what helps give the endospore heat resistance?
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high CA content and dipicolinic acid.
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archae (prokaryote) can live where?
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in extreme temperatures
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golgi body
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packaging
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medically important protozoa
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amoeboid protozoa-brain infections
flagellated protozoa- giardia apicomplexan protozoa- malaria |
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schistosoma japonicum
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common name: blood fluke. lives in: humans and snails. spread by: ingestion of fresh water containing larvae stage
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naked nucleocapsid viruses
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do NOT take cell membrane with
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what kind of virus takes part of the cell with it when it spreads?
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enveloped virus
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random facts about VIRUSES
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*DNA or RNA- coated with capsomers
*enveloped/ non enveloped *bacteriophage *reverse transcriptase *lysis or budding |
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reverse transcriptase
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the enzyme processed by retroviruses that carries out the reversion of RNA to DNA
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budding AKA exocytosis
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the process that releases enveloped viruses from the membrane of the host's cytoplasm.
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random facts about PRIONS
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*misshapen protein
*mad cow disease *creutzfield-jakob *scrappie- sheep *spongiform encephalitis *kuru tribe eating brains |
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randoms about VIROIDS
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*RNA
*Plant viruses |
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