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 contents |
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 |