Lecture 3 Flashcards
1
Q
taxonomy
A
- science of classification
- robert whittaker came up with the 5 kingdom system
2
Q
kingdom
A
- based on cell type: prokaryotic or eukaryotic
- cellular organization- unicellular/multicellular
- nutritional requirements- photosynthetic/nonphotosynthetic
- created by robert whittaker
3
Q
5 kingdoms
A
prokaryotae- prokaryotic organisms (bacteria)
- protista- eukaryotic, unicellular (amoeba)
- fungi- eukaryotic- yeast and mold
- plants- all plants- conifers, flowering plants
- animals- all animals, insects, worms, vertebrates
4
Q
domain
A
- based on ribosomal RNA sequence
- *bacteria
- *archaea
- *eukarya
5
Q
bacteria domain
A
- normal flora
- pathogens
- have peptidoglycan cell wall
6
Q
archaea domain
A
- prokaryotic
- unusual organisms
- extreme environment- hot springs, dead sea, salt lakes
- cell walls are made of pseudomurein
- ex. sulfolobus
- 3 groups: halophiles, thermophiles, methanogens
7
Q
eukarya domain
A
- protista
- fungi
- plant
- animal
8
Q
archaea domain: halophiles
-
A
- need high concentration of salt
- at least 30%
- ex. halobacterium (not a bacterium)
- live in salt lakes, dead sea
9
Q
archaea domain: thermophiles
A
- ex. sulfolobus
- lives in sulfur rich hot springs
- temperature 70 degree C
- pH=2
- thermophile and acidophile
10
Q
archaea domain: methanogens
A
- lives in swamps
- break down organic matter to make methane
- ex. methanobacterium (not a bacterium)
11
Q
classification of bacteria
A
- Bergey’s manual of systemic bacteriology has a classification scheme of evolutionary relationship among bacteria which is based on RNA sequence of bacteria
- species is defined as a group of organisms with similar characteristics when it comes to bacteria
- species of bacteria are subdivided into strains (subspecies)
- subspecies have organisms within the species with slightly different characteristics
- E. coli O157:H7 is a subspecies of E. coli that is found in the intestinal tract of cattle (normal flora) but is a pathogen for humans (bc of toxins it produces)
- transmitted in undercooked hamburgers
- causes bloody diarrhea (dysentery)
- different subspecies can be harmful while others not
12
Q
Bergey’s manual of determinative bacteriology
A
- has identification scheme for bacteria
- based on cell shape, gram reaction, and biochemical testing
- we look for enzyme activity
- urea -> urease -> ammonium ions
13
Q
serology
A
- diagnose infections, find enzyme activity
- antigen and antibody rxns in vitro (in tube, slide)
- antigen- foreign substance, non-self (ex. bacteria)
- immune system makes antibodies -> proteins
- antibodies bind to the antigen that stimulated their production and cause the antigen to agglutinate (clump)
- antibody is specific for the antigen that stimulated its production
- helps identify unknown bacteria, viruses and diagnose infections
14
Q
serology procedure
A
- bacteria are injected into a rabbit
- rabbits immune system makes antibodies
- they are released into the blood
- draw the blood and separate the serum
- that serum has the specific antibodies for that microbe
15
Q
slide agglutination test
A
- example of serological test
- 2 unknown bacteria -> we want to know if they are salmonella
- take a slide
- place a drop of unknown 1 on the end of one side of the slide and the other unknown on the other side
- place a drop of salmonella antiserum -> has antibodies against salmonella
- look for agglutination
- positive slide- the side with clumping is salmonella -> antibodies caused clumping bc it was specific to salmonella (vice versa)
- takes a few minutes
16
Q
rickettsias
A
- gram negative
- coccobacillus
- *obligate intracellular parasites -> bacteria has to get into the host cell to reproduce (uncommon)
- transmitted by insects such as ticks
17
Q
obligate intracellular parasites
A
- need a host cell in order to reproduce (uncommon)
- rickettsia rickettsii
- rocky mountain spotted fever
- southeastern parts of the country
- transmitted by ticks
- rash on palms and soles
- treated during the early stages of the disease
- can cause damage to the kidneys
18
Q
caulobacter
A
- aquatic environments
- *has a stalk
- uses stalk to attach
- attaches to algae and absorbs nutrients
19
Q
Rhizobium
A
- roots of plants beans and peas
- beneficial bacteria
- *converts nitrogen gas to ammonium ions -> nitrogen fixation
- ammonium ions are used by the plants to make protein
- beneficial to plants
- plants use ammonia to make proteins
- indirectly beneficial to humans and animals -> we eat the plants/cattle
20
Q
Neisseria gonorrhoeae
A
- pathogen
- gonorrhea- STD
- gram negative
- diplococci
- uses fimbriae to attach itself to the mucus membrane -> causes damage
- painful urination, discharge of pus
- if not treated -> pelvic inflammatory disease -> sterility
- treated with cephalosporin and doxycycilne
- also causes ophthalmia neonatorum -> eye infection of the newborn (picks up bacteria during birth)
- leads to blindness, antibiotics are placed in the eyes as prophylaxis
21
Q
neisseria meningitidis
A
- also is gram neg, diplococci, fimbriae
- some people are asymptomatic carriers
- have the organisms in their throat
- transmits bacteria in the aerosol (air)
- meningitis -> throat infection
22
Q
bordetella pertussis
A
- gram negative
- coccobacillus
- whooping cough
- grows on cilia lining the trachea
- accumulation of mucous -> cough
- DTP vaccine -> pertussis vaccine (dead)
- heat killed bacteria
23
Q
thiobacillus
A
- *chemoautotroph -> doesnt get energy from glucose
- gets energy from hydrogen sulfide
- found in soil
- gram negative
- rod shaped (bacillus)
24
Q
pseudomonas aeruginosa
A
- gram negative
- rod shaped
- opportunist -> causes problems when someones immune system is weak
- *makes a water soluble pigment (blue-green)
- causes skin infection if the skin is damaged (burn victims are vulnerable)
- burn and wound infections
- gentamicin, polymyxin
25
Q
escherichia coli
A
- gram negative
- bacilli
- normal flora of the intestinal tract
- opportunist (attacks in the intestinal tract when immune system is weak)
- makes vitamin K otherwise
- strain O157:H7 -> in the intestinal tract cattle -> pathogenic for humans
- bloody diarrhea
26
Q
salmonella typhi
A
- gram negative
- rod shaped
- causes typhoid fever
- found only in humans
- carriers have the bacteria in the gallbladder
- transmitted to other in contaminated food or water in poor sanitary practices
- fluoroquinilones, chloramphenicol
27
Q
salmonella enteritidis
A
- causes salmonellosis
- associated with chicken and cattle
- transmitted through undercooked contaminated food
- causes fever, abdominal pain, diarrhea
- fluid and electrolyte therapy -> then use antibiotics
- cooking the meat thoroughly can avoid this
- type of food poisoning
28
Q
opportunists
A
- klebsiella pneumoniae- normal flora
- proteus vulgaris
- enterobacter
- serratia marcescens- found in soil
- that all have endotoxin- lipid A
- if the endotoxin is released it causes septic shock
- nosocomial infections- from the hospital (due to weakened immune system)
- septic shock, pneumonia, urinary tract infections
- all gram negative
29
Q
yersinia pestis
A
- gram negative
- rod shape
- causes plague
- very deadly and contagious
- fleas from rats
- southwestern- transmission from squirrels, chipmunks
- transmitted with direct contact
- proliferate in the blood stream
- causes buboes (swelling of lymph nodes) -> bubonic plague
- mortality- 50 to 75%
- streptomycin and tetracycline- prophylaxis -> treatment
- pneumonic plague- if bacteria ends up in lungs -> spread through aerosol -> mortality rate is 100%
30
Q
vibrio cholerae
A
- gram negative
- bent rod shape
- single flagellum
- transmitted in contaminated water
- bacteria goes into intestine and produces a toxin -> cholera
- causes cholera
- cholera toxins attaches to cells lining the intestine -> stimulates the cells to release water and electrolytes
- profuse and watery diarrhea
- rice water stools -> mucus, epithelia cells, bacteria
- can recover without antibiotics
31
Q
chromatium*
A
- gram negative
- rod shape
- lives in lakes and pounds
- *anoxygenic photosynthesis
- it doesnt make O2 it makes sulfur in place of O bc it uses hydrogen sulfide in place of H2O
- hydrogen sulfide + CO2 -> sugar and sulfur
- typically plants/algae carry out -> water + CO2 -> sugar + O2
- anoxygenic photosynthesis
32
Q
bdellovibrio
A
- gram negative
- bent rod shape
- flagellum
- lives in soil
- *pathogenic to bacteria like e. coli
- goes into the periplasmic space of e. coli-> between outer and plasma membrane
- reproduces there
- uses up nutrients for e. coli
33
Q
desulfovibrio*
A
- sediments of lake and ponds
- *anaerobic respiration
- sulfur is the final electron acceptor -> inorganic
- bent rod
- gram negative
34
Q
cyanobacteria
A
- gram negative
- *carries on photosynthesis
- aquatic environments
- heterocysts- converts nitrogen to ammonium ions -> nitrogen fixation
- uses CO2 and water to make glucose and O2
- add oxygen and ammonium ions to atmosphere
35
Q
chlamydia
A
- gram negative
- *obligate intracellular parasite -> must go into host cell to reproduce
- two stages:
- elementary body- usually extracellular, dormant
- reticulate body- intracellular, active
- elementary body (outside host) comes in contact with eukaryotic cell -> goes into cytoplasm -> becomes reticulate body -> reproduces -> transforms back to elementary -> host cell breaks down -> reticulates are released
36
Q
chlamydia trachomatis
A
- spread through sexual contact
- most common STD
- causes urethritis
- treated by doxycycline
37
Q
chlamydia trachomatis
A
- common in the tropics, southwestern USA
- spread through direct contact, flies, towels
- causes eye infection, scarring of cornea
- blindness
- treated with tetracycline
38
Q
chlamydia trachomatis
A
- causes lymphogranuloma venereum- STD
- tropic, southeastern USA
- grows in the lymphatic system
- causes obstruction of lymph vessels
- treated with doxycycline
39
Q
spirochetes
A
- spiral shaped, axial filaments (movement)
- treponema pallidum- syphilis
40
Q
treponema pallidum*
A
- spirochetes
- syphilis
- STD
- primary stage- ulcer at site of inoculation
- secondary stage- bloodstream, rash on the skin and mucous membrane
- if secondary stage isnt treated -> no symptoms
- tertiary syphilis -> blindness, insanity, heart problems (no treatment)
- congenital syphilis- from the mother to fetus -> stillbirth
41
Q
borrelia burgdorferi
A
- spirochete
- causes lyme disease
- transmitted by ticks from field mice
- *rash at the bite site -> bulls eye rash
- flu like symptoms
- paralysis, heart problems
- arthritis
42
Q
leptospira interrogans
A
- spirochete
- causes leptospirosis
- *has hooked ends
- spread by infected or carrier dogs -> urine
- contaminated soil or water
- nonspecific symptoms
- damage to the liver and kidneys
43
Q
bacteroides*
A
- obligate anaerobes
- gram negative
- rod shape
- normal flora- intestinal tract and oral cavity
- opportunist- infects surgical wounds and puncture wounds
44
Q
mycoplasma pneumoniae*
A
- *no cell wall
- only has plasma membrane
- pleomorphic- has irregular morphology -> depends on the medium its growing on
- different arrangements
- transmitted by aerosol
- walking pneumonia- mild symptoms
- not bedridden
45
Q
clostridium*
A
- gram positive
- obligate anaerobe- can only grow in the absence of oxygen (most bacteria is facultative anaerobe)
- makes endospores
- found in soil -> deep enough there is no O2
- 3 pathogenic species
46
Q
clostridium tetani
A
- causes tetanus
- infects deep puncture wounds
- endospores becomes vegetative cells in the puncture wounds (found in soil)
- vegetative cells produces neurotoxin
- vegetative cells stay in the wound but the neurotoxin goes in the blood and nervous system
- causes spastic paralysis -> stiffness of the muscles
- lockjaw
- DTP vaccine- made up of tetanus toxoid (inactive)
- antitoxin- made up of antibodies specific for tetanus toxin
- antibodies are known as tetanus immune globulins (TIG)
47
Q
clostridium botulinum
A
- causes botulism
- caused by improperly canned food
- food poisoning
- endospores germinate into vegetative cells -> release neurotoxin
- causes flaccid paralysis
- double vision, drooping eyelids
- toxin is heat labile -> sensitive
48
Q
clostridium perfringens
A
- endospores are found in soil
- associated with gas gangrene
- gangrene- death of a tissue due to the loss of blood supply
- gangrene is caused by bullet wounds, frost bites
- once you have gangrene the bacteria infects and causes gas gangrene
- endospores end up in the dead tissue and germinate
- ferments carbohydrates and releases gas (also releases toxins)
- releases so much gas the skin rips
- toxins kill cells
- treatment is amputation
49
Q
bacillus anthracis*
A
- causes anthrax
- makes endospores
- facultative anaerobe
- gram positive
- associated with sheep and cattle
- endospores are in the soil
- animals eat the endospores -> go into blood
- endospores germinate into vegetative cells
- causes septicemia -> growth of bacteria in blood
- can be transmitted to humans (people who work with animals)
- cutaneous anthrax- bacteria infects cuts and breaks in skin
- inhalation anthrax- wools sorters disease -> dangerous form of pneumonia -> releases toxins
- treated with tetracycline (only in early stages)
50
Q
lactobacillus*
A
- gram positive
- rod shaped
- aerotolerant anaerobe- even in presence of O2 it doesnt use bc it has no ETC
- fermentation
- produces lactic acid
- normal flora- in intestinal tract, oral cavity
- used in yogurt production (alive)
- beneficial
51
Q
staphylococcus aureus*
A
- normal flora of skin
- gram positive
- cocci
- one strain causes food poisoning
- grows on custard, cream pie (sugars) -> toxins
- heat stable- reheating doesnt prevent food poisoning
- refrigerate the food product to prevent- bacteria grows slow
52
Q
streptococcus pyogenes*
A
- gram positive
- cocci in chains
- normal flora of throat
- transmitted in aerosol
- can cuase pharyngitis -> Step throat
- subspecies -> lysogenized strain -> causes scarlet fever
- lysogenized strain- phage DNA is inserted in the chromosome of the bacteria -> phage DNA has gene to make toxin
- erythrogenic toxin is produced (coded by phage DNA)
- bacteria stays in throat but toxin spreads
- causes pinkish red rash on skin
- tongue becomes red and enlarged -> Strawberry tongue
53
Q
corynebacterium diphtheriae*
A
- gram positive
- pleomorphic
- irregular morphology
- transmitted in aerosol
- causes throat infection
- tough grey membrane made up of fibrin, dead tissue, bacteria in the throat
- lysogenized strain (phage DNA) of this produces diphtheria toxin
- diphtheria toxin kills eukaryotic cells
- causes damage to the heart and kidneys
- DTP vaccine- made up of toxoid (inactivated toxin)
- treated with antitoxin (has anitbodies)
54
Q
mycobacterium tuberculosis
A
- acid fast bacteria
- has mycolic acid in cell wall
- rod shaped
- transmitted through aerosol
- can be dormant for years
- when immune system is weak -> bacteria is activated
- spread from lungs to other parts of body
- cough, weight loss, spitting blood
- consumption
- isoniazid, rifampin, ethambutol
- BCG vaccine
55
Q
mycobacterium bovis
A
- causes bovine tuberculosis
- tuberculosis in cattle
- transmitted in contaminated milk
- infects the bones
- used to be common before pasteurization
- causes hunchbacked deformation of spine
- BCG vaccine- avirulent strain of M. bovis (nonpathogenic strain is used)
56
Q
mycobacterium leprae
A
- causes leprosy or hansens disease
- optimum growth at 30C
- grows on face, fingers, toes (cooler parts)
- causes nodules and deformation of hands, face, feet
- transmitted in nasal secretions
57
Q
streptomyces
A
- beneficial
- live in soil
- most of the antibiotics
- makes a chemical -> geosmin -> gives soil its unique smell
58
Q
structure of viruses
A
- acellular
- no cytoplasm, no organelles, no plasma membrane
- either have RNA or DNA
- surrounded by a protein coat (capsid)
- some viruses have an envelope around capsid- proteins, carbohydrates, lipids
- envelope has spikes made up of protein or glycoprotein
- obligate intracellular parasites -> need host to reproduce
59
Q
bacteriophage
A
- complex virus
- has a capsid
- DNA is within the capsid
- capsid and tail fibers are attached to the sheath
60
Q
T even phages: lytic cycle
A
- T even phage
- attachment to e. coli cell
- bacterial cell must have the receptor for the phage (receptor has 2 functions)
- penetration- DNA of the phage is injected into the cytoplasm of the bacterial cell
- capsid stay on the surface (outside) of the bacterial cell
- biosynthesis of the phage- phage takes over the enzymes and ribosomes that are in the bacteria
- phage DNA is replicated and phage proteins are made using the bacterial enzymes and ribosomes
- maturation of the phage- assembly of the phage to make a complete phage particle
- release- bacterial cell breaks down and the phage particles are released -> go on to infect other bacterial cells
- reproduction of the phage results in the lysis of the cell -> lytic cycle
61
Q
lambda phage: lysogenic cycle and lytic cycle
A
- can reproduce using lytic cycle but also the lysogenic cycle:
- attachment to the bacterial cell (e. coli)
- penetration of the phage DNA into the cytoplasm of the bacteria
- phage DNA is inserted into the chromosome into the bacteria
- phage DNA is now known as the prophage -> the cell is known as the lysogenized cell
- lysogenized cell is more dangerous/pathogenic bc they make toxins bc the phage DNA has code for toxins
- lysogenized cell can reproduce itself normally -> prophage is passed on to daughter cells
- phage DNA is propagated
- phage DNA pops out of the chromosome sometimes -> this happens when the medium runs out of nutrients
- pops out of chromosome before it dies and then goes into lytic cycle -> biosynthesis
62
Q
animal viruses
A
- animal virus that infects humans
- papillomavirus (DNA virus)
- some subspecies of this cause common warts- legs and hands
- transmitted by contact
- treated with interferon
- different subspecies can cause genital warts
- finger-like projections (cauliflower)
- STD, can cause cervical cancer
63
Q
reproduction of DNA virus: papillomavirus
A
- virus attaches to host cell (must have receptor)
- penetration of the entire virus
- host cell is eukaryotic
- uncoding takes place in cytoplasm -> protein code is destroyed
- viral DNA is released from capsid
- viral DNA migrates to the nucleus of the host
- biosynthesis of the viral DNA
- viral DNA is transcribed to make mRNA
- viral mRNA is used on the ribosomes to make viral proteins
- maturation- different parts of the virus are assembled to make a complete viral particle
- release of the viruses and the host cell breaks down -> infects other cells
64
Q
virion=
A
virus
65
Q
poliovirus*
A
- RNA virus
- transmitted by fecal oral route -> contaminated food or water
- multiples in the throat and small intestine
- virus can get into the CNS and multiple in the neurons -> paralysis
- polio vaccine
66
Q
RNA virus reproduction: poliovirus
A
- RNA virus attaches to the host cell if it has the receptor
- penetration of the entire virus into the cytoplasm of the host
- uncoding
- capsid is broken down and viral RNA is released
- viral RNA has a gene that codes for RNA dependent RNA polymerase
- viral gene is translated and makes the RNA dependent RNA polymerase
- RNA dependent RNA polymerase uses RNA as a template to make a complementary strand of RNA
- many more copies of the viral genetic material (RNA) is made with this enzyme
- viral RNA is translated to make capsid proteins
- after biosynthesis there is maturation -> assembly of the virus -> viral RNA is enclosed with the protein code
- release of virus and host cell breaks down -> spread and infects
- **RNA virus never gets into the nucleus of the host
67
Q
retrovirus
A
- RNA- genetic material
- has the enzyme reverse transcriptase
- reverse transcriptase- uses RNA as a template to make a complementary strand of DNA
- capsid and envelope
- ex. human immunodeficiency virus (HIV)
68
Q
reproduction of retrovirus: HIV
A
- retrovirus attaches to the host if it has the receptor
- specific type of WBC has the receptor
- penetration of the virus
- uncoding- capsid and envelope of the virus is broken down -> viral RNA and reverse transcriptase is released
- viral RNA is used by the reverse transcriptase to reproduce -> makes DNA
- viral DNA migrates to the nucleus of the host
- viral DNA inserts itself into the chromosome -> becomes a provirus
- can stay dormant as a provirus
- sometimes the virus is activated -> biosynthesis
- viral RNA is made and makes viral proteins
- maturation- assembly to make a complete virus
- virus is released from the host cell through budding -> a segment of plasma membrane surrounds the virus and becomes the envelope during budding
69
Q
latent viral infection
A
- ex. herpes simplex virus
- herpes simplex virus 1 causes oral herpes
- very common
- people get it during infancy through direct contact
- virus ends up in neurons and stays dormant
- virus is activated by fever, sunburn, and stress
- once activated it grows in epithelial cells around the lips -> rash -> cold sores
70
Q
herpes simplex virus 2
A
- causes genital herpes
- STD
- virus stays dormant in some neurons
- activated by stress
- once activated vesicles show up in the area
- causes burning, difficulty walking
- treated with acyclovir -> prevents reproduction of virus (cant destroy)
71
Q
virus and cancer
A
- nucleated cells have proto-oncogenes
- proto-oncogenes control (regulate) cell growth
- if there is a mutation in proto-oncogenes -> abnormal proteins are made
- loss of control -> no regulation
- uncontrolled proliferation of the cell with mutation -> cancer
72
Q
mutations
A
- caused by chemicals, UV light, and viruses
- virus can mess up nitrogen base sequence once inserted
- epstein-barr virus- DNA virus -> causes cancer
73
Q
epstein-barr virus*
A
- DNA virus -> causes cancer
- dormant in some b lymphocytes
- most people have this
- transmitted in saliva
- causes infectious mononucleosis
- leads to burkitts lymphoma
- common childhood cnacer in africa
- average age of 7
- commin in africa bc malaria is common too
- EBV and plasmodium must be present bc they cause mutation in proto-oncogene: c-myc gene together
- loss of control of cell growth
- uncontrolled proliferation
- leads to cancer of jaw bone
74
Q
prions
A
- proteinaceous infectious particles
- proteins
- no genetic material
- cause scrapie in sheep
- scrape themselves against fences
- become paralyzed and die
- prions cause damage to the brain
- causes mad cow disease (bovine spongiform encephalopathy- BSE)- sponge like degeneration of the brain
- shake and shiver -> paralysis and die
- cows fed with sheep biproducts contaminated with infected prions caught disease
75
Q
creutzfeldt*
A
- mad cow disease can be transmitted to humans
- transmitted by contaminated hamburgers
- jakob disease
- causes damage to brain
- causes demetia
- die within year
76
Q
viroids
A
- naked piece of RNA (no coat)
- only difference between virus is that there is no coating (capsid)
- plant pathogen
- potato spindle tuber viroid
- damage to potato plants
- evolved from introns of plant cells
77
Q
synthetic drugs
A
- synthesized in the lab
- do not exist in nature
- isoniazid
- ethambutol
- sulfanilamide
- fluroquinolones
78
Q
isoniazid
A
- synthetic drug
- inhibits mycolic acid synthesis
- effective against mycobacterium tuberculosis
- mycobacterium is acid fast
79
Q
ethambutol
A
- synthetic drug
- inhibits mycolic acid
- also used to mycobacterium tuberculosis
- inhibits mycolic acid synthesis
80
Q
sulfanilamide
A
- synthetic drug
- inhibits folic acid synthesis
- inactivates the enzyme that converts PABA to folic acid
- used to treat UTIs
81
Q
fluroquinolones
A
- synthetic drug
- inhibits DNA synthesis
- used to treat typhoid fever and shigellosis
82
Q
penicillin
A
- antibiotics
- made by mold -> penicillium notatum
- inhibits peptidoglycan synthesis
83
Q
bacitracin
A
- antibiotic
- made by species of bacteria -> bacillus
- inhibits peptidoglycan synthesis
- used for topical applications (skin)
84
Q
polymyxin
A
- antibiotic
- made by bacteria -> bacillus
- damages plasma membrane
- topical treatment (skin)
85
Q
rifampin
A
- antibiotic
- made by bacteria -> Streptomyces
- inhibits RNA synthesis
- used to treated against mycobacteria tuberculosis
86
Q
antibiotics
A
- most are made by Streptomyces
- penicillin
- bacitracin
- polymyxin
- rifampin
87
Q
antifungal drugs
A
- amphotericin B
- nystatin
88
Q
amphotericin B
A
- antifungal drug
- made by streptomyces
- damages the plasma membrane
- treats systemic mycosis like histoplasmosis
89
Q
nystatin
A
- antifungal drug
- made by streptomyces
- damages plasma membrane
- treats candida infections
90
Q
antiviral drugs
A
- acyclovir
- zidovudine
91
Q
acyclovir
A
- antiviral drug
- inhibits the synthesis of viral DNA
- effective against herpes simplex virus
92
Q
zidovudine (AZT)
A
- antiviral drug
- AZT
- inactivates the reverse transcriptase (viral enzyme in retrovirus)
- can cause anemia in some cases
- used to treat HIV infection
93
Q
antiprotozoan drugs
A
- chloroquine
- metronidazole
94
Q
cholorquine
A
- antiprotozoan drug
- treats malaria caused by plasmodium
95
Q
metronidazole
A
- antiprotozoan drugs
- treats protozoa infestations like giardiasis, amoebic dysentery
- inhibits metabolism in an anaerobic environment
96
Q
antihelminthic drugs
A
- niclosomide
- praxiquantel
- mebendazole
97
Q
niclosomide
A
- antihelminthic drugs
- inhibits ATP synthesis in mitochondria
- treats tapeworm infestations
- tinea saginata, tinea solium
98
Q
praziquantel
A
- antihelminthic drugs
- damages plasma membrane
- treats fluke infestation
- westermani (lung fluke)
99
Q
mebendazole
A
- antihelminthic drugs
- inhibits microtubule formation
- treats roundworm infestation (nematodes)
- americanes, lumbricides
100
Q
resistance
A
- some bacteria develop resistance
- pick up R-plasmids- antibiotic resistance (more common)
- mutations can result in the overproduction of the enzyme that is being inactivated by the drug (less common)
101
Q
R-plasmid resistance
A
- r-negative cell (r-minus) -> doesnt have plasmid -> only has chromosome
- when cell is treated with penicillin -> damage to peptidoglycan cell wall -> death
- r-positive cell -> has the chromosome and r-plasmid -> r-plasmid has the code for the enzyme penicillinase
- gene is translated by cell and penicillinase is made and destroys antibiotic
- gram positive and resistant
102
Q
mutation resistance
A
- e. sulfanilamide
- under normal conditions the cell have the enzyme that converts para-amino benzoic acid (PABA) to folic acid
- folic acid is needed to make DNA
- wild type cells (no mutation)
- when treated with sulfanilamide -> sulfanilamide attached to enzyme and inactivates -> bacteria dies
- mutation causes overproduction of the enzyme -> more enzymes than there is sulfanilamide -> cannot inactive all enzymes
- continue to catalyze PABA to folic acid
103
Q
improper use of antibiotics causes resistance
A
- use of antibiotics in animal feed by farmers
- normal flora of the cattle is usually made up of sensitive bacteria and some resistant
- if animals are given antibiotics everyday -> it will kill sensitive bacteria
- resistant bacteria stay alive
- once the sensitive bacteria is killed the resistant bacteria has excess nutrients -> proliferate
- overgrowth of resistant bacteria
- eventually the entire normal flora of cow will be resistant
- can be transmitted to humans through meat and it will be harder to treat these infections in humans
