Micro Test 3 Test Questions – Flashcards
Unlock all answers in this set
Unlock answers| Moist heat sterilization |
| kills primarily by coagulating proteins (denaturation) caused by breakage of the hydrogen bonds that hold the proteins in their 3-diminsional structure. |
Pheonol & Phenolics
Phenol (carbolic acid): irritating, not used much anymore Phenolics (derivatives of phenol) contain a molecule that has been chemically altered to reduce its irritating qualitites or increase its antibacterial activity in comvination w/ a soap or detergent. |
phenolics: injure lipid-containg plasma membrane, causing leakage of cellular contents.useful against mycobacteria (tuberculosis & leprosy). recain active in presence of organic compounds, are stable, persist for long periods after application. |
bisphenols
contain 2 phenolic groups connected by a bridge. |
hexachlorophene: pHisoHex (lotion) used for surgical & hospital microbial control. Gram + staphylococci & streptococci are susceptible. triclosan: ingredient in antibacterial soaps. inhibits an enzyme needed for the biosynthesis of fatty acids which mainly affects the integrity of hte plasma membrane. Great against gram +, works well against yeasts a& gram-. |
| biguanides |
broad spectrum of activity mode of action primarily affecting bacterial cell membranes. most effective against gram + chlorhexidine alexidine
|
Halogens
|
iodine chlorine |
iodine
tincture: in solution in aqueous alcohol iodophor: combination of iodine & organic molecule which I2 is released slowly. |
iodine: impairs protein synthesis & alters cell membranes by forming complexes w/ amino acids & unsaturated fatty acids.
|
| why do autotrophs have the simplest nutritional requirements? |
| they make their own food and down need to obtain it. |
| contrast lithotroph & photoautotroph |
photoautotroph-light source of energy, CO2 source of Carbon, H2O electron donor lithotroph-use of an inorganic compound as a source of energy, CO2=carbon source, electron donor |
| how do lithotroph & autotroph make ATP |
lithotroph-protein motive force drives synthesis of ATP photoautotroph-produce ATP through photophosphorylation of organic compounds |
| how do photoautotroph & lithotrophs fix carbon (convert inorganic C to organic) |
photo- anabolically, photosynthesis litho-inorganic oxidation |
| principle enzyme in CO2 fixation |
| carbonic anhydrase |
| ex of oxidation processes performed by chemoautotrophs, where does it occur in cell. |
fixation of CO2-stroma (The supportive framework of an organ (or gland or other structure), usually composed of connective tissue) denitrification iron oxidation |
| sergei Winogradsky discovered chemolithoautotrophy? |
| his theory first developed while studying sulfur-oxidizing bacteria. in zurich he did monumental work on bacterial nitrification. ammonia-nitrite-nitrate |
| how do sulfur-oxidizing bacteria & nitrate-reducing bacteria compare? |
sulfur-oxidizing: electron donor & energy needed, ATP consumed nitrate-reducing: facultative anarobes, produce ATP, use ETC |
| how does bacterial photosynthesis compare to green plant? |
bacteria: 1 photosystem, H2X, membrane bound, cyclic, NADPH, anoxygenic green: 2 photo system, H2O, membrane bound, non-cyclic, NADPH, oxygenic |
| what do green and purple use as electron donor in place of H2O |
purple: H2, H2S, S green: H2, H2S, S |
| where does photosynthesis occur |
| cell membrane |
| name 3 environmental gaseous toxins/poisons on physical parameters to which m.o have adapted |
| heat, salt, cold temp, acidity |
| what type of bactera are methanogens? physiological processes? |
| extremophile, produce methane gas & detoxify waste, gron on CO2 & H2 as energy source |
| how could methanogens be considered chemoautrophs? anaerobic respiration? |
anaerobic b/c don't need O2 as electron acceptor ; have organic donor, chemoautotroph b/c organic C source |
| methyltrophs |
| can use reduced one carbon compounds (methane) as C source, can degrade methane |
| voltas experiment? |
| invented battery, static electricity, methane was his combustable air |
| 3 principle biogeochemical cycles |
1: carbon cycle: methylotrophs, methanogens 2: nitrogen cycle: N2 fixation, ammonification 3: sulfur cycle |
| which did Winogradsky demonstrate? |
| nitrogen ; sulfur |
anaerobic ; aerobic processes in cycles
carbon cycle |
1: aerobe: respiration (CH2O to CO2), photosynthesis (CO2 to CH2O), methylotrophs (CH4 to CO2) 2: anaerobe: anaerobic respiration/fermentation (CH2) to CO2) bacterial photosynthesis (CO2 to CH2O), methanogens (CO2 to CH4) |
anaerobic ; aerobic processes in cycles
nitrogen cycle |
1: aerobe: nitrification (NH3 to NO2 -), 2: anaerobe: N2 fixation, ammonification, nitrification, denitrification |
anaerobic ; aerobic processes in cycles
sulfur cycle |
1: aerobic: desulfurylation, sulfate reduction 2: anaerobic: desulphurylation, sulfate reduction |
| sludge digester ; winogradsky column |
sludge digester: produce methane from waste. layers=CH4, scum, supernatant, actively digesting sludge, stabilized sludge; producer=H2, CO2, acetate, formate *carbon cycle Winodgradsky column: biogeochemical system. layers=O2, H2O, photosynthetic bacteria, CO2 + H2S, disulfibrio, lactic acid, anaerobic baceria, mud *sulfur ; nitrogen cycle |
| diff. b/w dis and assimilatory N2 pathways |
disimilatory (ex nitrate respiration ; N2 fixation) use the subtrates to as a place to dump ilectrons ; generate energy assimilatory: mehtods for taking a nutrient in the sould, making it into cell ; using it for biosynthesis of macromolecules |
| N2 fixation |
| conversion of atmospheric nitrongen in compounds, such as ammonia. |
| ammonification |
| the conversion of organic nitrogen to ammonium by action of decomposers |
| nitrification |
| biological oxidation of ammonia to ammonium to nitrite to nitrate |
| denitrification |
| loss or removal of nitrogen, conversion of nitrate to nitrogen gas |
| sterile |
| free from bacteria |
| axenic |
| not contaminated w/ living organisms |
| aseptic |
| procedure formed under sterile conditions |
| disinfectant |
| substances applied to non-living objects to destroy mo living there |
| degerming |
| removal of mo from skin |
| pasteurization |
| removing harmful pathogens from food using heat |
| sanitary |
| hygenic and clean |
| germicide |
| substance or other agent that destroy harmful mo, antiseptic |
| chemotherapeutic agent |
| treatment of disease using chemical agents |
| antibiotic |
| inhibits bacterial growth or kills bacteria |
| qualities of ideal antimicrobial agent? |
readily available inexpensive chemically stable easily administered nontoxic and nonallergenic selectively toxic against a broad range of pathogens |
| what are the 3 types of antimicrobial agents? |
static: antimicrobials that inhibit microbial growth w/o killing cidal: kill microbes lytic: kill microbes by lysing *distinguish by examing effect of the antimocrobial agent on a growing bacteria culture |
| MIC: minimum inhibitory concentration test |
| test for biostatic (growth stopping) avtivity of liquid antimicrobial |
| MBC: minimum bactericidal concentration |
| lowest conc. of an antimicrobial agent required to kill a particular bacterium |
| phenol coefficient |
| measure of the bactericidal activity of a chemical compound in relation to phenol, disenfecting power |
| diff classes of antibiotics |
| static, cidal, lytic |
| oligodynamic actin? chemicals inhibit, effect? |
the inhibitying or killing of m.o by use of very small amounts of chemical substancce metal ions |
| what is the active ingredient in lysol |
| alcohol |
what kind of agents are betadine zephiran mercurachorme merthiolate triclosan chlorinedioxide |
betadine: provide one iodine topical antiseptics antiseption (PVP) zephiran: benzalkonium chloride mercurochrome: merbromin triclosan: polychlorophnoxyphenol chlorinedioxide: disinfectant
|
| how many ways can heat be used to control or destroy pop. of mo? |
2 moist heat (steam, autoclave) dry heat |
| pasteurization vs. sterilization |
past. is carried out for prolonged time @ 170 deg and is supposed to kill only heat susceptible organisms and their spores ster. works at a temp of 250 deg ; kills all mo |
| 2 types of pasteurization used by food industry, conditions |
1: vat pasteurization: heat milk in large tank for at least 30 min 2: high temp short time pasteurization (HTST): higher temp (101 deg) for less time (15 sec) and rapid cooling
|
| autoclave formula |
| *PV=nRT |
| physical agents used to control/preserve mo |
| pasterization, dehydration, dessication, freezing, acidity, osmotic pressure, radiation, ultrafiltration (smoking) |
| membrane filtration |
| forces pressure or conc gradient leads to speration through semipermeable membrane, ability to purify, seperate, |
| cold-sterilization |
| glutaraldehyde used for minor process in which sterilization is carried out @ low temp w/ help of chemicals, radiations and membranes |
| 2 types of radiation |
1: UV: lamps used to sterilize workspaces, germicidal wavelengths causes adjacent thymine molecules on DNA, inhibits DNA replication 2: Gamma radiation: ionizing energy, low penetration + high dose rates, alters chemical bonds |
| father of chemotherapy |
| Sidney Farber |
| salman waksman |
| streptomycin |
| alexander flemming |
| penicillin |
| paul ehrlich |
| treatment of syphilis "magic bullet" |
| underlying principle behind all chemotherapeutic agents |
| kill cancer by treating them w/ chemicals that interfere w/ cell division |
| 3 antibiotics producing mo, common? |
staphylococcus aureaus bacillus cereus streptomyces griseus
*selective toxicity |
| secondary metabolite |
organic compounds that are not directly involved in the normal growth, development of organism
pigment: distinction antibiotics morphine: pain control tetrodotoxin: poison |
| analog |
| any of two organisms in differnt species or animal which differ in structure but similar in funtions |
| how are anaologs used as chemotherapeutic agents |
| antimetabolites |
| mechanisms of pronosil |
| stimulate pagocytosis |
| B-lactam antibiotic |
| broad class of antibiotics consisting of als that contain a B-lactan ring in structure |
| how has 6-amino-penicillin been modified? |
| subjected to esterification, amidation, and hydroxy anidation rxn |
| mode of action of penicillin |
| inhibit formation of cell wall as bacteria grow and divied. inhibit formation of peptidoglycan cross links |
| target ; example antibiotics |
cell wall: phenols cell membrane: alcohols proteins: heavy metals mucleic acid: gluteraldehyde amino acids: formaldehyde |
| pro vs euk antibiotics |
| riboomes, initiator tRNA, initiating elongation and termination |
| broad spectrum antibiotics |
| antibiotic acts against a wide range of disease-causing bacteria |
| quinolone antibiotic mechs |
| synthetic broad spectrum, intro of nalidixic acid, prevent bacteria from duplicating |
| bactrim |
synthetic antibiotic mech of action, combo |
| neosporin |
| bacitracin, neomycin, polymixin B |
| problems w/ antibiotics |
antibiotic resistance, side effects, super bugs after animals have been fed antibiotics over a period of time, they retain the strain of bacteria which are resistant to antibiotics. these bacteria proliferate in the animals. bacteria resistant transfer to humans |
| resistant to penicillin |
1: penicillinase emersed as defense mechanisms in habitat 2: innapropriate prescription of antibiotics |
| What are some mechanisms currently used to overcome the problem of antibiotic resistance |
| good hygeine, cooking meat thoroughly, take antibiotics only when necessary, WHO, strenthen action of existing antibiotics by modifying them to the bacterial enzymes that cause resistance |
| Why is clavulanic acid used in combination with some ?-lactam antibiotics? |
| both have lactam ring |
What are MRSA ; VRE |
MRSA: methicillin resistant staphylococcus aureus VRE: vancomycin-resistant enterococc |
| How does Hospital Associated MRSA differ from Community Associated |
hospital MRSA: troublesome in hospitas, passable w/ open wound and weak immune system community: MRSA infections in healthy people who have not been hospitalized or had a medical procedure (such as dialysis or surgery) within the past year. |
| Thermal death point |
| lowest temp at which all mo in a liquid suspension will be killed in 10 min |
| Thermal death time |
| minimal lenght of time for all bacteria in a liquid culture to be killed at a given temp |
| Decimal reduction time (DRT or D value) |
| the time in min in which 90% of a pop of bacteria at a given temp will be killed. |
| surfactants |
decrease sufrace tension among molecules of a liquid soaps and detergents |
