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microbiology #2
test 2
Question | Answer |
---|---|
aggregation of cells arising from single parent cell | Colony |
collection of microbes living on a surface in a complex community | biofilm |
source of Carbon (CO2) for growth requirements | Autotroph, heterotrophs (organic compounds) |
sources of energy for growth requirements | chemotrophs (chemicals)(organism use), phototrophs (light) (plant use) |
grow in the presence of oxygen | aerobes |
an organism that cannot tolerate oxygen | Anaerobes |
microorganism that can live with or without oxygen | facultative anaerobe |
microorganism with which prefers anaerobic conditions but can tolerate exposure to low levels of oxygen | aerotolerant anaerobe |
microorganism that require requires low levels of oxygen | microareophile |
anabolism ceases because of insufficient _____ | nitrogen |
chemical requirements for growth | nitrogen, phosphorus, sulfur, trace elements, growth factors |
required in minute amounts for the growth requiremnts | trace elements |
necessary organic chemicals that cannot be synthesized by certain organisms | growth factors |
used by mycoplasmas (bacteria) for cell membranes | cholesterol for growth factors |
component of proteins | amino acids for growth factors |
functional portion of cytochromes in electron transport system | heme for growth factors |
precursor of NAD and NADP | niacin (nicotinic acid, vitamin B3) for growth factors |
component of coenzyme A | Pantothenic acid (vitamin B5) for growth factors |
precursor of folic acid, which is involved in metabolism of one carbon compounds & nucleic acid synthesis | para-aminobezoic acid (PABA) for growth factors |
components of nucleic acids | purines, pyrimidines for growth factors |
utilized in transamination syntheses of amino acids | pyridoxine (vitamin B6) for growth factors |
precursor of FAD | riboflavin (vitamin B2) for growth factors |
utilized in some decarboxylation reactions | thiamine (vitamin B1) for growth factors |
temperature affects what in proteins? | the 3D structure |
what is temperature sensitive in a cell? | lipid containing membranes of cells & organelles |
if temperature is too low in cell, what happens? | membranes become rigid & fragile |
if temperature is too high in cell, what happens? | membranes become too fluid |
what is the ideal temperature for bacteria? | 37C |
most humans and pathogens are classifed as? | mesophiles |
organisms are sensitive to change in what kind of environment? | acidity |
neutrophiles have what kind of pH? | neutral |
acidophiles have what kind of pH? | low pH |
alkalinophiles have what kind of pH? | High pH |
pressure exerted on a semipermeable membrane by a solution containing solutes that cannont freely cross membrane | osmotic pressure |
lower solute concentrations, cells swell | hypotonic solution |
greater solute concentration, cell shrivels | hypertonic solution |
restricts organisms to certain environments, obligate & facultative halophiles | physical effects of water |
cell is normal, fluid is equal on the inside and the outside | isotonic solution |
a microbe harms another organism | antagonistic relationship |
members of an association receive benefits that exceed those that would result if each lived by itself | synergistic relationship |
organisms become interdependent and rarely live outside the relationship | symbiotic relationship |
complex relationships among numerous microorganisms, form on surfaces, medical devices, mucous membranes of digestive system, dental plaque is considered this | biofilm |
progenitor is termed a________ | colony forming unit (CFU) |
pure cultures are composed of cells arising from a single ______ | progenitor |
_______technique prevents contamination of sterile substances or objects | Aseptic |
2 common isolation techniques | streak plates, pour plates |
Bacterial inoculum intoduced into nutrients called ____ | media |
only _____ of bacteria are culturable | 5% |
6 types of culture media | defined, complex, selective, differential, anaerobic, transport media |
medium in which the exact chemical composition is known | defined media |
exact chemical composition is unknown, contains nutrients from yeast, beef, soy or proteins, supports growth of wide variety of microorganisms, used to culture organisms with unknown nutritional needs | complex media |
allows certain types of organisms to grow, and inhibits the growth of other organisms | selective media |
Mannitol Salt Agar (MSA) has a high salt content, which represses the growth of bacteria other than _______ | Staphylococci |
differentiate closely related species of bacteria, organisms will produce characteristic changes or growth patterns that are used for identification or differentiation | differential media |
Blood agar (BAP) visualizes the ability of bacterial species to____ | lyse red blood cells |
crystal violet kills ______ | gram positive bacteria |
e. Coli is usually Gram _______ | negative |
obligate anaerobes must be cultured in the absence of free oxygen | anaerobic media |
petri plates are incubated in ____________ culture vessels, sealable containers that contain chemicals that reduce the oxygen | anaerobic |
which is th emost common anaerobic? | Palladium |
used by hospital personnel to ensure clinical specimens are not contaminated and to protect people from infection, rapid transport of sample is important | transport media |
examples of transport media | blood culture bottles, thioglycollate broth |
stores for short period of time | refrigeration |
stores for years | deep-freezing |
bacteria freeze better in the presence of what? | glycerol |
freeze drying in to a powder, stores for decades | lyophilization |
time required for a bacterial cell to divide/ grow, dependent on chemical & physical conditions | generation time |
microbial growth curve | lag phase, log (exponential) phase, stationary phase, death (decline) phase |
direct methods not requiring incubation | microscopic counts |
stained prokaryotes & large eukaryotes | microscopic counts |
electronic counters for measuring microbial reproduction | flow cytometry, coulter counter |
direct methods require _____ | incubation, serial dilution & viable plate counts |
indirect methods require ______ | turbidity |
what is turbidity measured by? | spectrophotomoeter |
what can grow in a petri plate ona laboratory table? | an aerobic bacterium |
This statement "in the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals" describes which of the following? | streak plate |
superoxide dismutase neutralizes ____ | singlet oxygen |
the most reactive of the 4 toxic forms of oxygen is? | the hydroxyl radical |
microaerophiles that grow best with a high concentration of carbon dioxide in addition to a low level of oxygen are called? | capnophiles |
organisms that preferentially thrive in icy waters are described as _______ | psychrophiles |
barophiles cannot ______ | cause disease in humans |
an organism that cannot exist in the presence of oxygen | obligate anaerobe |
when the exact chemical composition is know it is called a ? | defined medium |
most useful in representing population growth on a graph | semilogarithmic graph using a log scale on the y-axis |
best method for counting fecal bacteria from a stream to determine the safety of the water for drinking | membrane filtration |
a device that directly counts microbes as they pass through a tube in front of an electronic detector | coulter counter |
the ability to respond to changes in population density | quorum sensing |
what do cells require for a redox reaction? | electrons |
toxic form of oxygen, molecular oxygen with electrons that have been boosted to a higher energy state | singlet oxygen |
what essential element do all cells recycle from amino acids & nucleotides? | nitrogen |
what are small organic molecules that are required in minute amounts for metabolism | growth factors |
the lowest temperature at which a microbe continues to metabolize is called its _________ | minimum growth temperature |
__________ pigments protect many phototrophic organisms from photochemically produced singlet oxygen | carotenoid |
microbes that reduce to N2 to NH3 engage in nitrogen __________ | fixation |
a student observes a researcher streaking a plate numerous times, flaming the loop between streaks. The researcher is likely using the ______ method to isolate microorganisms | streak plate |
chemolithotrophs acquire electrons from ________ compounds | inorganic |
destroys most microorganisms & viruses on non-living tissues (particularly pathogens) | Disinfection |
destruction of ALL microorganisms on an object | sterilization |
sterile microbial control | disinfection & sterilization |
reduction in the microorganisms & viruses on living tissues (particularly pathogens) | antiseptic |
mechanical removal of microorganisms (handwashing) | Degerming |
using heat to destroy pathogens & reduce microbial load in food products, slows down food spoilage | pasteurization |
reduction of pathogens from objects to meet public health standards | sanitation |
most resistant to sterilization | prions |
least resistant to sterilization | enveloped viruses |
what biosafety level: handling microbes that do not cause disease in humans, ex: yogurt factories | BSL-1 |
bio-safety level: handling moderately hazardous agents | BSL-2 |
bio-safety level: all manipulations of microbes done in safety cabinets | BSL-3 |
denature proteins, interfere with integrity of cytoplasmic membrane & cell wall, disrupt structure & function of nucleic acids | effects of high temperature on cells |
used to disinfect, sanitize, sterilize & pasteurize, denature proteins & destroys cytoplasmic membranes, more effective than dry heat | moist heat |
kills vegetative cells | boiling |
methods of microbial control using moist heat | boiling, autoclaving, pasteurization |
high heat, high pressure, over boiling | autoclaving |
autoclave conditions | 121C, 15 psi, at least 15 minutes |
heat destroys pathogens, reduces the number of spoilage micoorganisms in food, not sterilization | pasteurization |
decreases, microbial metabolism, growth & reproduction, refrigeration halts growth of most pathogens, some microbes can multiply in refrigerated foods | refrigeration & freezing |
_______ inhibits growth as a result of removal of water | Desiccation (drying) |
_______ is used for long term preservation of microbial cultures, prevents formation of damaging ice crystals | Lyophilization |
pass non-sterile solution through a membrane with small pores that trap microbial contaminents | filter sterilization |
introduces so much DNA damage that the cell dies, superficial sterilization, not common in hospitals only works on surfaces | non-ionizing radiation/ UV radiation |
commonly used in the healthcare setting, labs & homes, have disagreeable odor & possible side effects, ex: pine-sol | phenol & phenolics |
swabbing skin with _____ prior to injection removes most microbes, ex: ethanol, isopropanol | alcohol |
iodine tablets, iodophores, chlorine treatment, bleach, the addition of fluoride to water & toothpaste, are all examples of what | halogens |
hydrogen peroxide can disinfect & sterilize surfaces, not useful for treating open wounds | oxidizing agents |
good degerming agent, but not antimicrobial | soaps & detergents |
heavy metals used for disinfection | silver nitrate |
______ is commonly used to prevent blindness in newborn babies caused by N. gonorrhoeae | silver nitrate |
________ contains 1 molecule of mercury, and is used to preserve vaccines | Thimerosal |
Formalin is considered a ______ | Aldehyde |
________ is used in embalming & in disinfection of rooms & instruments | Formalin |
methods for evaluating disinfectants and antiseptics | in-use test |
accurate determination of proper strength and application procedure for each specific situation | in-use test |
what kills microorganisms on laboratory surfaces? | disinfectants |
what best describes the disinfecting of cafeteria plates? | sanitization |
the microbial death rate is used to measure the efficiency of ________ | detergent, antiseptics and sanitization techniques |
the endospores of which organism are used as a biological indicator of sterilzation | bacillus stearothermophilus |
what functions as an auotclave? | pressure cooker |
the preserve beef jerky from microbial growth relies on which method? | desiccation |
which type of radiation is more widely used as antimicrobial technique? | electron beams |
what substances would most effectively inhibit anaerobes? | hydrogen peroxide |
what adjective best describes a surgical procedure that is free of microbial contaminants? | aseptic |
a sample of E. coli has been subjected to heat for a specified time, and 805 of the cells have been destroyed, what best describes this event? | decimal reduction time |
what is active against bacterial endospores? | ethylene oxide |
what disinfectant acts against against cell membranes? | phenol |
what disinfectant contains alcohol? | tincture of bromine |
what antimicrobial chemical has been used to sterilize spacecraft? | ethylene oxide |
what class of surfactants is most soluble in water? | quaternary ammonium compounds |
who invented penicillin? | Alexander Flemming |
effective antimicrobial agent that is more toxic to the pathogen than to the host | selective toxicity |
numerous differences between _________ bacteria and ________ hosts provides many targets | pathogenic, eukaryotic |
Beta-lactams: penicilin, cephalosporin, carbapenem, vancomycin, bacitracin inhibit what? this also weakens the cell wall | peptidoglycan formation |
antimicrobial agent that inhibits protein synthesis by blocking the tRNA docking site | tetracycline |
antimicrobial agent that inhibits protein synthesis by changing the shape of the 30s ribosomal subunit | aminoglycoside |
what is a good target for antimicrobial activity? | ribosomes |
why are ribosomes a good target for antimicrobial activity? | changes shape of subunits within ribosomes to interfere with binding, prevent elongation of proteins & prevents enzymatic activity |
_________ attaches to ergosterol in fungal membranes, forming pores which disrupts the cytoplasmic membrane | Amphotericin B |
what is effective when pathogen and host metabolic processes differ? | Antimetabolic agents |
structurally similar to an enzyme required to synthesize folic acid, necessary to make DNA & RNA nucleotides | sulfonamides |
what happens when you over prescibe broad spectrum drugs? | antibiotic resistance |
example of a broad spectrum drug | sulfonamides, erythomycin, tetracyline |
bacterial lawn exposed to dics impregnated with antimicrobial agents, the larger the zone of inhibition the more effective | kirby-bauer disk diffusion |
the lowest concentration of antimicrobial able to kill all bacteria in a well | minimum inhibitory concentration (MIC) |
routes of administration for antimicrobial drugs | topical application, oral route, intramuscular administration, intravenous administation |
side effects of administration of antimicrobial drugs | toxicity, allergies, disruption of normal microbiota |
why must you finish a course of prescribed antibiotics | because of the development of resistance in populations |
________ denatures Beta-lactam penicillins making it ineffective | Beta-lactamase |
_______ remove drugs from inside of the cell | efflux pump |
forming an enzyme that destroys or deactivates the drug will... | alter the target of the drug, efflux pumps remove drugs from inside the cell, slow down metabolism, which creates fewer targets, alter the binding site of the drug |
Alters penicillin-binding protein in the membrane Gene encoded on a plasmid | S. aureus mecA gene |
Proteins that traverse the inner and outer membrane – remove antibiotic from the cell | Genes encoded on plasmids |
Bacterial cells in biofilm become “sessile”, or metabolically inactive – decreases drug targets available, If a cell reverts to metabolic activity, becomes susceptible again | Slow down metabolism |
Genotypic changes, Polymicrobial infections increase genetic transfers between species | Antibiotic resistance |
Phenotypic changes, Sessile cells are metabolically inactive, Transient tolerance | Antibiotic tolerance |
Maintain high concentration of drug in patient for sufficient time, Use antimicrobial agents in combination, Use antimicrobials only when necessary, Develop new variations of existing drugs, Search for new antibiotics | Retarding Resistance |
diffusion/ dilution tests that expose pathogens to antimicrobials are designed to ________ | determine which drug is most effective against a particular pathogen & determine the amount of a drug to use against a particular pathogen |
ina kirby-bauer susceptibility test, the presence of a zone of inhibition around disks containing antimicrobial agents indicates________ | that the microbes does not grow in the presence of the agents |
the key to successful chemotherapy is _______ | selective toxicity |
why are sulfonamides effective? | humans & microbes use PABA differently in their metabolism |
resistance to one antimicrobial agent because of its similarity to another antimicrobial agent | cross resistance |
multiple drug resistant microbes ________ | frequently develop in hospitals |
what is most closely associated with a beta-lactam ring? | penicilin |
drugs that act against protein synthesis | aminoglycosides |
drugs that neutralize the acidity of ________ prevent viral uncoating | phagolysosomes |
___________ can be used to stop microbial replication | nucleotide analogs |
drugs containing __________ retard viral growth by blocking the reproduction of essential viral proteins | protease inhibitors |
PABA is used to ________ | synthesize folic acid |
the interplay between drugs that results in efficacy that exceeds the efficacy of either drug alone | Synergism |
most numerous & diverse group of cellular microbes, thrive in various habitats, only a few are capable of colonizing humans & causing disease | prokaryotes |
what bacteria are endospores produced by? | bacillus & clostridium |
defensive strategy against unfavorable conditions, are often difficult to kill | endospores |
how do prokaryotes reproduce? | asexually (binary fission) |
2 types of asexual reproduction done by prokaryotes? | binary fission (most common) & budding (usually done by fungi) |
modern prokaryotic classification is based on? | genetic relatedness of rRNA sequences |
three domains of prokaryotic classifcation | archaea, bacteria, eukarya |
lack true peptidoglycan, cell membrane lipids have branched hydrocarbon chains | common features of archaea |
what is not known to cause disease? | archaea |
2 types of extremophiles | thermophiles, halophiles |
DNA, RNA, cytoplasmic membranes & proteins do not function well below 45C | thermophiles |
inhabit extremely saline habitats, depend on greater that 9% NaCl to maintain integrity of cell walls, may contain red or orange pigments | halophiles |
largest group of archaea, convert carbon dioxide, hydrogen gas & organic acids to methane gas | Methanogens |
live in the colons of cows, primary source of environmental methane | methanogens |
Different types of gram positive bacteria: Firmicutes | clostridium, mycoplasma, bacili |
Different types gram positive bacilli bacteria | bacillus, listeria, lactobacillus, streptococcus, staphylococcus |
Different types of gram positive actinobacteria | corynebacterium, mycobacterium, actinomyces, nocarida, streptomyces |
rod shaped, obligate anaerobes, produce toxins that cause disease in humans, endospores survive harsh conditions | clostridia |
clostridia is associated with what bacteria/ diseases | Cdiff, tetanus, botulism |
what is also know as "walking pnemonia" or pnemonia acquired during the summer? | mycoplasma pneumoniae |
smallest free living cells, lack cell walls | mycoplasmas |
this gram positive bacteria is classified as endospore forming aerobes and facultative anaerobes | bacillus |
contaminates milk/ meat products, capable of reproducing under refrigeration, can kill the fetus in pregnant women if it crosses the placenta | listeria monocytogenes |
grows in the mouth, stomach, intestinal tract & vagina, rarely causes disease, inhibits the growth of pathogens within the body, used in the production of various foods | Lactobacillus |
Streptococcus pyogenes "group A" can cause ______ | strep throat or necrotizing fascitis |
Streptococcus agalactiae "Group B" can cause ________ | newborn meningitis |
Staphylococcus epidermidis can cause ______ | commensal skin colonizer |
Staphylococcus aureus is _________ | common pathogen, multi-drug resistant (MRSA, VRSA) |
what does the gram positive bacteria: corynebacterium diptheriae cause? | diptheria-throat infection |
filamentous rods, slow growth partly due to mycolic acid in its cell walls | mycobacterium |
mycobacterium tuberculosis is called? | TB |
mycobacterium leprae is called? | leprocy |
the gram positive bacteria actinobacteria is also known as? | phylum |
form branching filaments resembling fungi, producers of antiniotics, acid-fast | actinobacteria (phylum) |
examples of actinobacteria | actinomyces, nocardia, streptomyces |
produces numerous antibiotics | streptomyces |
largest and most diverse group of bacteria | proteobacteria |
proteobacteria is gram_______ | negative |
5 classes of proteobacteria | alpha, beta, gamma, delta, epsilon -proteobacteria |
associated with plants, nitrogen fixation | rhizobium |
spread by arthropods, associated with rocky mountain spotted fever | rickettsia |
can contaminate milk, causes miscarriges, cause brucellosis | Brucella |
rhizobium, rickettsia & brucella are all categorized as what gram-negative bacteria | alphaproteobacteria |
causes gonorrhea & meningitis | neisseria |
causes pertussis "whooping cough" | bordetella |
legionella, enterobacteriacae & psuedomonads are all categorized as what gram negative bacteria? | gammaproteobacteria |
what gram-negative bacteria causes legionnaire's disease, american legion | legionella |
what gram-negative bacteria causes intestinal bacteria to develop? | enterobacteriacae |
what gram-negative bacteria is associated with important human pathogens? | psuedomonads |
what does the gram negative bacteria vibrio parahaemolyticus cause? | "summer diarrhea" oysters |
what does the gram negative bacteria yersinia pestis cause? | plague, black death |
what gram negative bacteria causes urinary tract infections, wound infections, respiratory infections, bacteremia, ear infections | psuedomonas aeruginosa |
infects the stomach, causes ulcers, stomach cancer | hylicobacteria pylori |
hylicobacteria pylori is classified as what class of bacteria? | epsilonproteobacteria |
venereal disease, causes neonatal blindness | chylamydia trachomatis |
what gram negative bacteria is chylamydia trachomatis classified as? | phylum chlamydiae |
the bacteria that causes syphilis, neurosyphilis | treponema pallidum |
lyme disease, spread through ticks | borrelia |
what 2 bacteria are classified as phylum spirochetes? | treponema pallidum & borrelia |
what bacteria lacks peptidoglycan cell walls? | Chylamydia |
Archaea are classified into phyla based primarily ______ sequences | rRNA |
________ inhibit extremely saline habitats, such as the Great Salt Lake | Halophiles |
Pigments in _________ in phototrophic bacteria trap light energy for metabolic processes | thylakoids |
Most cyanobacteria form _________ in which nitrogen fixation occurs | heterocysts |
what are giant bacteria that are large enough to be seen without a microscope? | Selenomonas |
the type of reproduction in prokaryotes that results in a palisade arrangement of cells is called? | snapping division |
the thick walled reproductive spores produced in the middle of cyanobacterial filaments is called? | terminal endospores |
what best describes stiff, spiral-shaped prokaryotic cells? | spirilla |
what can remain alive for decades, remain alive in boiling water, exist in a state of suspended animation? | endopores |
how is halobacterium distinctive? | it is absolutely dependent on high salt concentrations to maintain its cell wall |
photosynthetic bacteria that also fix nitrogen are ___________ | cyanobacteria |
what genus is the most common anaerobic human pathogen? | bacteroides |
flexible spiral shaped prokaryotes are ______ | spirochetes |
bacteria that convert nitrogen gas into ammonia are __________ | nitrogen fixers |
the presence of mycolic acid in the cell wall characterizes what? | mycobacterium |
3 eukaryotic microorganisms | protozoa, algae, fungi |
single copy (haploid) occurs through what process? | meiosis |
what reproduces mostly through meiosis | fungi |
2 copy (diploid) occurs through what process? | mitosis |
what reproduces through mitosis? | algae, protozoa |
cell partitions that replicate DNA equally between 2 nuclei, exact copies of parent nucleus, remain diploid | mitosis |
4 phases of mitosis | prophase, metaphase, anaphase, telophase |
occurs before mitosis begins, DNA & organelles are duplicated | interphase |
Dna condenses, nucleus dissolves, mitotic spindle moves to poles | prophase |
DNA lines up in the middle of the cell, mitotic spindle attaches | metaphase |
DNA pairs split, move towards poles | Anaphase (mitosis) |
nucleus reforms, organelles and DNA cluster in poles, cleavage furrow forms | telophase (mitosis) |
nuclear division that partitions parent cells into 4 haploid cells, 2 stages-meiosis I and meisis II-each stage includes 4 stages PMAT | Meiosis |
homologous chromosomes pair to form tetrads | prophase I |
tetrads align in the middle of the cell, mitotic spindle attaches | metaphase I |
chromosomes split, move towards poles | Anaphase (meiosis) |
nucleus reforms, chromosomes cluster in poles, cleavage furrow forms | telophase (meiosis) |
DNA not replicated, one chromosome in each cell, mitotic spindle moves toward poles | prophase II |
chromosomes aligns in the middle of the cell, mitotic spindle attaches | metaphase II |
division of a cells cytoplasm | Cytokinesis |
3 characteristics of protozoa? | eukaryotic, unicellular, lack a cell wall |
most protozoa are _______ | chemoheterotrophic |
what is the motile feeding stage in protozoa called? | trophozoite |
what is the resting stage in protozoa called? | cyst |
fungi cell walls are typically composed of _____ | chitin |
chemoheterotrophic, do not perform photosynthesis, related to animals, produce antibiotics, decomposer | fungi |
divided into cells by internal cross walls in fungi | septate hypha |
no septate partitioned in fungi | aseptate hypha |
all have some means of asexual reproduction, most also reproduce sexually | fungi |
some yeasts produce long filaments called _______ | psuedohypha |
fungal mating types designated as "+" and "-_ | sexual spore formation |
classifications of fungi | zygomycota, ascomycota, basidiomycota, deuteromycetes |
recieves nutrition from dead matter | saprobes |
what fungal classification is saprobes classified under? | zygomycota |
most human pathogens, food spoilage, beneficial fungi includes penicillium | ascomycota |
what are beneficial fungi? | penicillium, saccharomyces |
what category are the fungi: penicillium, saccharomyces classified under? | ascomycota |
the yeast responsible for making bread, beer & wine | saccharomyces |
what fungal classification is mushrooms under? | basidiomycota |
partnership between fungi & photosynthetic microbes, fungus provides nutrients, water, & protection and photosynthetic microbes provide carbohydrates & oxygen | lichens |
simple, eukaryotic phototrophs, carry out oxygenic photosynthesis using chlorophyll, aquatic | algae |
classifications of algae | green, red & golden algae |
share numerous characteristics with plants, green algae | chlorophyta |
marine, red algae | rhodophyta |
component of marine phytoplankton, major source of world's oxygen | chrysophyta |
_________ are animals that carry pathogens | arthropod vectors |
2 types of arthropod vectors | mechanical & biological |
what kind of arthropod vector carry pathogens? | mechanical vectors |
what kind of arthropod vector carry/ host pathogens, transmit disease through bites | biological vectors |
what 2 classes of arthropods do disease vectors belong to? | arachnida & insecta |
examples of arachnida | ticks, mites |
Examples of insecta | fleas, flies, mosquitos |
haploid nuclei contain how many sets of chromosomes? | 1 |
multiple nuclear divisions without cytoplasmic divisions result in cells called______ | coenocytes |
the type of asexual fungal spore that forms within hyphae is called a ________ | chlamydospores |
what does a phycologist study? | alterations of genes in algae |
the stemlike portion of a seawood is called its ________ | stipe |
carrageenan is found in the cell walls of which group of algae? | red algae |
chrysolaminarin is a storage product found in which group of microbes? | golden algae |
what feature characterizes diatoms? | chlorophylls a and c & carotene |
amoebae include microbes with _______ | threadlike psuedopods |
what is common to mitosis & meiosis? | spindle |
what taxon is characterized by "hairy" flagella | stramenopila |
minuscule, acellular, infecious agents, cause infections of humans, animals, plants & bacteria, no cytoplasmic membrane, cytosol, organelles,"non-living" cannot reproduce on its own | viruses |
virus particles contain genetic material & a ___________ | capsid shell |
this genetic material filled capsid is called ________ | nucleocapsid |
provide protection for viral nucleic acid, means of attachment to host's cells | capsids |
a "phage" virus that only infects bacterial cells | bacteriophage |
acquired from host cell during viral replication or release, composed of host phospholipid bilayer & proteins, not on all viruses | the viral envelope |
what are viruses classified by? | nucleic acid (RNA/DNA), presence of envelope, shape (helical, cylindrical, icosahedral), size |
what is dependent on hosts' organelles and enzymes to produce new virions | viral replication |
2 types of viral replication | lytic & lysogenic |
viral replication usually results in death & lysis of host cell | lytic replication |
5 stages of lytic replication cycle | attachment, entry, synthesis, assembly, release |
modified replication cycle, infected host cells, grow & reproduce normally for generations before they lyse, usually incorporate viral genetic material into the DNA of the host | lysogeny |
when the cell is infected with an inactive lysogenic virus, that cell has a ________ | latent infection |
viruses cause ________% of human cancers | 20-25 |
specific viruses are known to cause ______% of human cancers | 15 |
some carry copies of oncogenes as part of their genomes, some interfere with tumor repression, some promote oncogenes already present in host | role of viruses in cancer |
3 different mechanisms in which animal viruses enter cells | direct penetration, membrane fusion, endocytosis |
viruses that enter cell with capsid intact are ______ | uncoated |
direct penetration is done by? | phages only |
membrane fushion is done by? | enveloped viruses |
endocytosis is done by? | enveloped and non-enveloped viruses |
entry & uncoating is done by? | animal viruses |
DNA viruses often enter the _______ | nucleus |
RNA viruses often replicate in the ______ | cytoplasm |
similar to replication of cellular DNA, viral genome replicated in the nucleus, viral proteins are made in the cytoplasm | dsDNA viruses |
cells do not use ssDNA, host enzymes produce DNA strand complementary to vital genome to form dsDNA molecule, dsDNA used for viral replication & transcription | ssDNA viruses |
contains reverse transcriptase that generates DNA from RNA | retroviruses +ssRNA |
strand of genome acts as mRNA | dsRNA viruses |
RNA-dependent RNA polymerase generated +ssRNA | -ssRNA viruses |
enveloped viruses are often released by ________ | budding |
naked viruses are released by _________ | exocytosis or lyse |
________cannot grow in standard microbial media | viruses |
how are viruses cultured? | media consisting of mature organisms, embryonated eggs, cell cultures |
how are phages grown? | in bacteria, in liquid cultures or on agar plates |
lysis of bacteria produces ______ | plaques |
pros of culturing viruses in embryonated chicken eggs? | inexpensive, sterile, some vaccines are prepared in chicken cultures |
what virus is common culture in chicken eggs? | the influenza vaccine |
very small, circular pieces of RNA that are infectious & pathogenic in plants, lack capsid, not pathogenic in humans | viroids |
proteinaceous infectious agent | prion |
most famous prion disease? | variant Creuztfeldt-jakob disease (vCJD) "Mad Cow disease" |
functional proteins that contain α-helics | cellular PrP |
disease causing proteins, contain β-pleated sheets | prion PrP |
________ causes cellular PrP to refold into prion PrP, normal proteins become non-functional | Prion PrP |
what disease does the poxviridae virus cause? | orthopoxvirus (smallpox) |
what diseases does the herpesviridae virus cause? | herpes, chicken pox, mono, birth defects |
what disease does the papillomaviridae virus cause? | human papilloma virus |
what disease does the picornaviridae virus cause? | polio, hepitis B, common cold |
what disease does the coronaviridae virus cause? | coronavirus (common cold) |
what disease does the retroviridae virus cause? | AIDS |
What disease does the orthomyxoviridae virus cause? | influenza virus (Flu) |
what disease does the filoviridae viruse cause? | filovirus (ebola) |
a naked cell has no ______ | membranous envelope |
when a eukaryotic cell is infected with an enveloped virus and sheds viruses slowly over time, this infection is called a_________ | persistent infection |
another name for a complete virus is ________ | virion |
what virus can be latent? | herpesviruses |
a clear zone of phage infection in a becterial lawn is called a ________ | plaque |