microbiology final

Question Answer
1.) bacteriophage virus that infect bacteria
2.) protein coat of a virus capsid
3.)a virus with a membrane around the protein coat envelope
4.) how viruses are classified helical viruses, polynedral viruses, enveloped viruses, complex viruses
5.) what type of parasites viruses are obligatory intracellular parasites
6.) the ending of a virus family name viridae
7.) types of nucleic acids are found in viruses DNA & RNA but never both
8.) what form the nucleic acids might be found in? double stranded DNA, single stranded DNA
double stranded RNA, single stranded RNA
9.) how viruses might be cultured? viruses must be grown in living cells *animal & plant viruses may be grown in cell culture
10.) transduction the transfer of DNA from one cell to another by bacteriophage
11.) the term for the entrance of animal viruses into host cells receptor-mediated endocytes/fusim
12.) how non-enveloped viruses exit host cells non-enveloped viruses are released through ruptures in the host cell plasma membrane it contrasts to budding, this type of release, unusually results in the death
13/14.) the name given to viruses that cause tumors oncogenic viruses
15.) prions proteinaceous infectious particles
16.) the temperature classifications of microbes psychrophiles, mesophiles, thermophiles
17.) the pH range that bacteria grow best between pH 6.5 & 7.5
18.) halophile an organism that requires a high salt concentration for growth
19.) how bacteria are classified by their oxygen requirements *obligate aerobes-require oxygen
*facultative anaerobes-absence of oxygen
*obligate anaerobes-unable to use molecular oxygen
20.) where biofilms frequently form? usually attach to a surface such as a rock in a pond, a human tooth or a mucous membrane *form on almost all indwelling medical devices, including mechanical heart valves, catheters
21.) what is used to make liquid medium hard in plates? adgar
22.) complex medium made up of nutrients including extracts from yeasts, meat, or plants, or digests of proteins from those and other surfaces
23.) what might be put in selective media to inhibit the growth of unwanted organisms? salts, dyes, & other chemicals
24.) what differential medias are used for make it easier to distinguish colonies of desired organism from other colonies growing at the same plate
25.) how to microbiologist obtains pure culture? steak plate method
26.) generation time the time required for a cell to divide
27.) different phases of bacterial logarithmic growth *lag phase-little of no cell division
*lag/experimental growth phase-cells begin divide, period of growth
*stationary phase-period of equilibrium
*death phase/logarithmic decline phase-period of logarithmic decrease in a decrease in a bacterial populat
28.) the direct methods of measuring bacterial growth plate counts, serial dilletions, pour plate method, spread plate method, filtration, most probable number method, direct microscopic count
29.) what type of method uses a spectrophotometer for measuring bacterial growth? turbidity
30.) thermal death time minimal length of time for all bacteria in a particular liquid culture to be killed at a given temp.
31.) the most effective method for moist heat sterilization? autoclave
32.) pasteurization climinative pathogenic microbes in milk
33.) filtration passage of a liquid or gas through a screenlike material with pores small enough to retain microorganisms
34.) why do microorganisms die in high salt or sugar concentrations? high concentrations of these substances create a hypertonic environment that cause water to leave the microbial cell *this process resembles preservation by desiccation in that both methods deny the cell the moisture it needs for growth
35.) the types of radiation and what they do to cells *ionizing radiation-high energy radiation with a wave length less than 1nm; causes ionization, xrays and gamma rays are ex:
*non ionizing radiation-short-wavelength radiation that does not cause ionization; ultraviolet radiation is an example…
continued… microwave-electromagnetic radiation with wave length between 10^-1 & 10^-3m
36.) disinfectant and antiseptic bacteria disinfectant-any treatment used to inanimate objects or kill or inhibit the growth of microorganisms
antiseptic-a chemical method for disinfection of the skin or mucous membranes
37.) how do phenols affect bacteria? (carbonic acid) phenolics increase its antibacterial activity in combination with a soap or detergent. phenolics exert antimicrobial activity by injuring lipid-containing plasma membranes which result in leakage of cellular sat_flash_1s
38.) what are bisphenols commonly used in? hexachlorphene-ingredient of a prescription lotion, pH isottex (used for surgical and hospital microbial control procedures)
39.) how does alcohol affect bacteria? usually protein denaturation, but alcohol can also disrupt membranes and dissolve many lipids, including the lipid component of enveloped viruses
40.) which heavy metals can affect bacteria? silver, mercury, copper
*otigodynamic action-ability of very small amounts of heavy metals, especially silver and copper to exert antimircobial activity
41.) what do soaps and detergents do? important function in the mechanical removal of microbes through scrubbing *soap breaks the oily films into tiny droplets
42.) quats most widely used surface-active agents are the cationic detergents especially the quaternary ammonium compounds (quats)
43.) what are nitrates and and nitrites used for? added to many meat products as a substitute for oxygen under anaerobic conditions
44.) how do aldehydes affect bacteria?
(45.) most resistant to disinfectants-gram negative)
(46.) most resistant structures/organisms to disinfection-psuedomonas, burkholdeia, mycobacrterium)
(47 next slide)
used extensively to preserve biological specimens and inactive bacteria and viruses in vaccines
48.) repressible genes
(47.) structure of the bacterial chromosome-single long continuous frequently circularly arrange threads of dbl stranded DNA)
mechanism that exhibits gene expression and decreases the synthesis in enzymes
49.) inducible genes process that turns on the transcription of a gene or genes
50.) operon the operator and promoter sites and structural genes they control
51/52.) types of mutations 1.) base substitution-most common type of mutation involving single base pairs (point mutation). (a single base at one point in the DNA sequence is replaced with a different base)
continued… 2.)missense mutation-change in DNA where the base substitution results in amino acid substitution the synthesized protein
3.) nonsense mutations-a base substitution resulting a nonsense codon
continued.. 4.) framshift mutations-changes in DNA, one or a few nucleotide pairs are deleted or inserted in the DNA
5.)spontaneous mutation-mutation that occurs without a mutagen
6.)mutagens-an agent in the enviroment that brings out mutations
53.) what type of mutation does UV light cause? skin cancer-mistakes in replication
54.) why a low rate of mutation can be beneficial to an organism random mutations at low frequency is an essential aspect of the adaptation of species to their environment for evolution requires that genetic diversity be generated randomly and at a low rate
55.) what type of plating is used to detect auxotrophic mutants?
58.) what is it called when bacterial DNA is transferred to another bacterium by a bacteriophage? transduction
59.) plasmid a small circular DNA molecule that replicates independently of the chromosomes
60.) transposons a small piece of DNA that can move from one DNA molecule to another
61.) first antibiotic discovered penicillin
62.) 5 modes of action of antimicrobial drugs on bacterial cells 1.)inhibtion of cell wall synthesis:penicillins,cephalosporons,becitracin,vanomycin
2.) inhibtion of protein synthesis: chloramphenical, erythromycin,tetracycline,streptomycin
3.)inhibtion of nucleic acid rep. and transcription:quinolones,rifampin
continued.. 4.)injury to plasma membrane:polymyxin B
5.)inhibtion of synthesis of essential metabolies:sulfnilamide,trimethorpim
63.) antibiotics that affect a broad range of bacteria broad specturm antibiodies
64.) bacteriostatic and bactericidal bacteriostatic-prevent microbes from growing
bactericidal-kill microbes directly
65.) which organism we have produced over half of the antibodies screening soil samples/streptomyces
67.) antibiotics that inhibit cell wall synthesis cephalosporins, polypeptides, penicillins
68.) which antibodies inhibit protein synthesis chloramphenicol, aminoglycosides, tetracyclines, streptogramins, macrolides, oxazolidines
69.) antibiotics cause injury to cell membranes lipopeptides
70.) what sulfamides do to microorganisms? treats microbial diseases
71.) which drugs affect sterols in fungal membranes the principal sterol is ergosterol. antifungals which include members of the polyene, azol, and allylamine groups
72.) griseofulvin inhibits microtubule formation, superficial dermatophytes
78.) communicable disease a disease that is spread from one host to another
79.) classification diseases by frequency of occurance incidence: fraction of a population that contracts a disease during a specific time
prevalence:fraction of a population having a specific disease at a given time
sporadic disease:disease that occurs occasionally in a population
continued… endemic disease:disease constantly present in a population
epidemic disease:disease aquired by many hosts in a given area in a short time
pandemic:worldwide epidemic
herd immunity:immunity in most of a population
80.) herd immunity immunity in most of a population
81.) systemic infection an infection throughout the body
82.) what a disease that can be transmitted to humans by animals is called zoonoses
83.) different ways a disease can be transmitted direct:requires close association between infected and susceptible host
indirect:spread by fomites
droplet:transmission via airborn droplets *transmission by in inanimate reservior (food,water,air)
84.) disease acquired in the hospital nosocomial infections
85.) emerging infectious disease diseases that are new, increasing in incidence, or showing a potential to increase in the near future
86.) who is credited with the beginning of epidmeiology? john snow
87.) what causes impetigo? staph aureus
88.) scalded skin syndrome staph aureus
89.) which streptococci are most pathogenic to humans? streptococcus phylogeas group A (beta hemo)
90.) pseudomonas aeruginosa swimmers ear
91.) shingles chicken pox, herpes, zoster
92.) opthalmia neonatorum nisseria gonohria-neworns comes from mother
93.) bacterial meningitis haemophilus influenza, neisseria streptococcus meningitis, precmonia
94.) tetanospasmin toxin clostridium tentane
95.) clostridium botulinum produces.. botulism
96.) why the salk and sabine vaccines were developed polio virus
97. lyssavrius causes.. rabies
98. what usually causes sub-acute bacterial endocarditis alpha hemolytic streptococcus
99.) bacillus anthracis causes.. anthrax
100. yersinia pestis causes.. the plague
101. lyme disease is caused by what? borrelia burgdorferi
102. what causes borrelia burgdoferi? shape of lyme disease-spirochete

Leave a Reply

Your email address will not be published. Required fields are marked *