Flashcard Micro Exam 2 PDF

what statement about viruses is false? a) viruses must invade a living host cell to reproduce b) viruses are generally smaller and less complex than bacteria c) viruses are classified as prokaryotesd) viruses have genese) viruses are parasites c) viruses are classified as prokaryotes which struct...

what statement about viruses is false? a) viruses must invade a living host cell to reproduce b) viruses are generally smaller and less complex than bacteria c) viruses are classified as prokaryotesd) viruses have genese) viruses are parasites c) viruses are classified as prokaryotes which structures are found in all viruses?a) protein capsidb) nucleic acid genomec) lipid enveloped) peptidoglycan cell walle) polysaccharide capsule a & b Norovirus is a naked RNA virus. It is infamous as a cruise ship virus because it is very contagious and infection results and vomiting and diarrhea which term best describes the capsid of Norovirus.a) complexb) icosahedralc) filamentousd) helical b when a naked DNA virus infects a host cell, what biological molecules must be synthesized to create new virus particles (3) DNA, RNA, proteins norovirus is a naked RNA virus. when the virus binds to its receptor on gastrointestinal epithelial cells, it enters via the process of _____ endocytosis DNA polymerase enzyme function DNA Synthesis RNA Polymerase enzyme function RNA synthesis ribosomes enzyme function protein synthesis what can a living host cell do with an RNA template synthesize new proteins during HIV infection, which viral enzyme makes a DNA copy of the viral RNA genome reverse transcriptase protease inhibitors are drugs that are used to inhibit viral multiplication in individuals infected with HIV which step of the HIV infectious cycle is inhibited by a protease inhibitor Assembly and maturation of new HIV virus particles during what stage of the virus reproduction cycle are mutations first introduced RNA synthesis prions are infectious, neural proteins that reproduce to the process of _____ conversion which structure of a virus is composed of a phospholipid bilayer with viral spike proteins Envelope which host enzyme is used by DNA viruses during infection to make copies of the viral genome DNA polymerase all viruses have _____ & _____ nucleic acid genome & protein capsid some viruses have this, but not all lipid envelope classifications of viruses (3) 1. genome: DNA or RNA2. capsid: helical or polyhedral 3. envelope: naked or enveloped virus that infects bacteria bacteriophage cytopathic effects viruses cause additional problems to cells outside of killing them latent state viruses hide in nerve and become reactivated months/years later 5 steps of virus infection 1. adsorption2. entry & uncoating3. synthesis4. assembly 5. release tropism & affects what human cell defines the host cell specifically of a virus.affects t cells what type of cell uses fusion enveloped what type of cell uses endocytosis naked nucleic acid synthesis make copies of viral genome protein synthesis (3 things ) make viral enzymes make viral capsomersmake viral envelope spikes and insert in host membrane RNA viruses require what for synthesis viral enzyme rna retroviruses require viral enzyme but enzyme doesn’t directly synthesize rna, it makes dna instead latency virus is dormant integration viruses incorporate genomes into host chromosomes budding release of enveloped viruses lysis cell dies prions infectious protein particles put microbes in order from most resistant to least resistant1. enveloped viruses2. fungal spores3. endospores4. prions5. protozoan cysts 4. prions3. endospores5. protozoan cysts2. fungal spores1. enveloped viruses 5 levels of decontamination sterilization disinfection antisepsissanitation degermation sterilization destruction or removal of all viable microbes, including endospores and viruses from inanimate objects disinfection destruction or removal of vegetative pathogens, but not endospore from inanimate objects sterilization example surgical instruments sterilized in autoclave disinfection example spray bleach on countertop after handling raw meat antisepsis & example destruction or inhibition of vegetative pathogens, but not endospores from living tissuesex: an alcohol, wipe used on skin before a needle injection sanitation & example production and the number of microorganisms to acceptable levels on an inanimate objectsex: dishes are washed with soap and hot water in a restaurant degermation & example reduction in the number of microorganisms on living tissuesex: wash hands after being in contact with fomites, and public places moist heat is used to what & ex denature or coagulate microbial proteins dry heat is used to what dehydrate cells, de nature proteins in oxidize biological moleculestemp and time of exposure is greater than moist heat endospores forming bacteria are difficult to kill because of ___ and ____ Sporecoat and metabolic inactivity thermoduric resistant to heat killing boiling water moist heatdoesn’t kill endospores decontamination achieved at 100C for 30 mins steam under pressure moist heatautoclave sterilizes inanimate objects destroys endospores tyndallization intermittent steam for 30-60 mins over 3 daysallows endospores to germinate after cooling and then another cycle of steam kills vegetative cells pasteurization disinfection of beverages at 71.6 for 15 seconds cold temperatures Reduce metabolism and inhibit growth lyophilization freeze drying hypertonic environments High solute concentrations will inhibit microbial growth by increasing osmotic pressure non-ionizing radiation UV rays cannot penetrate and affect upper surface of objects to damage microbial DNAdo not kill, bacterial endospores filtration physically removes microbes and endospores from fluids Magic bullet A chemical that could kill a pathogen without harming the host- selective toxicity for pathogen- non-toxic to host- easily delivered- stable/retained- No resistance Paul EHRLICH Created Salvarsan for the treatment of syphilis Alexander Fleming discovered penicillin Howard Flory and Ernest chain Took Flemings findings and created penicillin bactericidal kills bacteriostatic inhibits broad spectrum antibiotics can cause superinfection bacterial targets (4) - protein synthesis, ribosomes - folic acid synthesis- DNA/RNA synthesis - cell wall synthesis peptidoglycan set synthesis of bacteria is an important antibiotic target NAG-NAM glycan chains are the rows of bricksPeptide cross lakes are the mortar hold bricks together without mortar, the brick wall is unstable without cross-links Peptidoglycan is unstable GLUCOSYLTRANSFERASE Builds glycan chains “george lays bricks” transpeptidase makes peptide cross-links between glycan chains penicillin inhibits ___ transpeptidase, makes peptidoglycan w/o cross links target for penicillin penicillin binding protein (PBP) beta lactam antibiotics penicillin and amoxicillin ciproflaxacin (target,interferes, cause target: DNA gyraseinterferes with: DNA synthesis DNA damage causes cell death Rifampin (target, interferes, cause) target: RNA polymeraseinterferes: RNA synthesiscauses cell death protein synthesis inhibitors azithromycin: binds to 50sneomycin: binds to 30sdoxycycline: binds to 30s folic acid synthesis inhibitors prevent the metabolism of DNA, RNA and amino acids and microbes by inhibiting to key enzymes in the same pathway sulfamethoxazole interferes with PABA to DHPA trimethoprim interferes with DHFA to THFA isoniazid interferes with mycolic acid synthesis azoles common anti fungal agents are antivirals agents virus specific or broad spectrum? virus specific fusion inhibitor (target, interferes) (enfuviritide) target: HIV gp41prevents binding to receptor and inhibits virus entry reverse transcription inhibitor (target, interferes) (azidothymidine) target: HIV RTinhibits viral genome replication protease inhibitors (target, interferes) (saquinavir) target: HIV protease inhibits virus assembly/maturation anti-microbial resistance mechanisms (4) efflux pops, inactivating enzymes, alternative enzyme, mutation clavulanate beta lactamase inhibitors methicillin not inactivated by beta lactamase vancomycin last resort treatment for MRSA noncompliance patients do not finish full course combination therapies Suppress antibiotic resistance Point source epidemic High numbers of cases that go down towards the end common source epidemic Approximately normal graph propagated epidemic (transmission) Low to high increasing graph endemic steady state sporadic pops up epidemic outbreak pandemic Worldwide incidence New cases in timeframe prevalence Total existing cases john snow discovered that cholera outbreak was caused by the water pump Robyn, Warren and Barry Marshall discovered bacteria called H. pylori was etiologic agent of gastric ulcers robert koch etiologic agent nosocomial healthcare acquired infections biological vector blood feeding living animals zoonotic infections animals disease reservoir - can be living or nonliving- Where the pathogen survives and multiplies- allows transmission to host placental during pregnancy perinatal during birth reservoir where disease exists in nature access portal of exit Transmission to other host endotoxin produces systematic effects, which do what Side effects at an unsafe level enterotoxins - fluid secretion and peristalsis and G1 tracked- transmission -Food poisoning neurotoxins - paralysis - Weaken host- tetanus cytotoxins - cell lysis/tissue damage- invasion, nutrients, weaken host, transmission- whoopingcough exotoxins Proteins excreted by some Grandos and gram-negative that are toxic and small doses and specific to cell type exoenzymes damage host tissues, and promote invasion mucinase digest mucus hyaluronidase hyaluronic acid collagenase collagen a pathogen must be able to (5) 1. Access portal of entry.2. Colonize host.3. Survive host defense.4. Cause damage.5. Access portal of exit biosafety level 1 open bench biosafety level 2 gloves & coat biosafety level 3 safety cabinets & vaccines biosafety level 5 isolation & decontamination infection - microbes that may have potential to cause disease into the host and begin to multiply- May or may not be associated with symptoms disease - Infecting microbes cause cell/tissue damage in host- Signs and symptoms of illness appear endogenous infections caused by microbes that reside in host infectious dose ID minimum number of microbes at the portal of entry required to establish infection