INFECTION AND RESPONSE Flashcards
a pathogen is
health is-
poor health can be caused by pathogens or….x3
pathogens may be….
pathogens can be spread by x3
a microorganisms that cause infectious disease- spreads communicable disease
state of mental + physical wellbeing
-poor diet, stress, life situation
virus
bacteria
protists
fungi
-direct contact-eg hiv
-water- drinking/ bathing it
eg cholera spread by drinking water contaminated with sewage of sufferer-
-air-carried in air, in water droplets- then breathed in eg influenza
bacteria make u feel ill by… x3
-difference btwn bacteria and virus
how do viruses cause illness x4
reproduce rapidly
producing toxins
that damage tissues
-virus X reproduce by themselves- only reproduce in host cell
-virus much smaller than bacteria (1/100th the size)
-invade host cell
-reproduce rapidly inside host cell using cells machinery
-many viruses in cell-when virus leaves cell- cell bursts- releasing the viruses- the cell dies
-cell damage causes illness
are protists eukaryotes/prokaryotes
-what is a parasite
eukaryotes + most are unicellular
-protist that lives on/in organism - causing damage. normally transferred by a vector which doesn’t get the disease.
some multicellular fungi are made of hyphae- what does these thread like structures do-
hyphae penetrate human skin + plant surface- cause disease
how can humans prevent spread of pathogens x6
-basic hygiene- wash hands(eg prepping food)
-provide clean drinking water-eg chlorine in uk water kill microbes
-reduce direct contact btwn individuals- eg condom
-isolate patients with communicable disease
-vaccination- in uk poultry vaccinated against salmonella
-destroy vectors- insecticides/ destroy habitat
explain the interaction of diseases x4
-ppl w/ a disease eg hiv more likely to get an infectious disease
hiv causes defective immune system
-one disease can be the cause of another-
eg hpv common but can cause cerbvical cancer in some ppl
-some diseases can be triggered by immune system- body infected with pathogen- immune system fights it but triggers an allergy
-physical illness can lead to mental illness eg depression
2 viral diseases in humans
-can antibiotics kill viruses
measles
hiv
-no (Viruses don’t have cell walls that can be attacked by antibiotics-surrounded by protective protein coat)
MEASLES
-symptoms
-how is it spread
-is measles serious
-are ppl vaccinated- if so when
-what can measles lead to- x2
-fever then also red skin rash
-by inhalation of droplets from sneezes and coughs of infected person
-yes, can be fatal if complications arise
-most vaccinated when young bcse its serious illness
-inflammation of the brain
-pneumonia- lung infection
HIV
-symptoms
-how is it spread
-How can it be controlled
-what does HIV do if not controlled
-what is late stage HIV
-another name for late stage HIV
-whats dangerous about late stage HIV
-flu like illness- goes after few weeks
-sexual contact-unprotected/ exchange of body fluids eg HIV infected blood, when druggies share needles
-antiretroviral drugs which stop virus replicating
-attacks immune system
-immune system severely damaged so white blood cells can no longer destroy pathogen- cannot fight infections others easily can or cancers
-AIDS
-can easily contract infections (like tb) and may develop cancer
-pros of antiretroviral drugs x2
-con
-stop virus multiplying so immune system isn’t damaged
-don’t develop aids- live normal life expectancy
-not a cure- must always be taken
2 bacterial diseases
-are these communicable or non
salmonella
ghonorrea
-communicable
SALMONELLA
-what is salmonella
-how is it spread x2
-give an example
-what do the salmonella bacteria do
-symptoms x4
what is done to prevent spread of salmonella in uk
-food poisoning
-ingesting food contaminated w/ salmonella bacteria
-or on food (that got contaminated when) prepared in un-hygenic conditions
-same chopping board for raw chicken and other food w/out cleaning it
-secrete toxins that cause symptoms
-fever
-abdominal cramps
-vomiting
-diarrhoea
-poultry are vaccinated against salmonella (so we don’t eat infected chicken)
GONORRHOEA
-what type of disease is this
-how is it spread
-symptoms x2
-how was it treated-y not now
-How can spread be controlledx2
STD
-sexual contact
-thick yellow discharge from vagina/penis
-pain on urinating
-EASILY treated w/ antibiotic PENICILLIN - many resistant strains appeared
- treatment w/ antibiotics
ppl who do unprotected sex tested and treated w/ antibiotics to kill it
-use barrier method of contraception
MALARIA
-what pathogen causes malaria
-is it communicable
-is it serious
-what does it cause
-describe how malaria’s spread-4 steps
-why is the mosquito a vector
-how to control spread of malaria x3
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-protists
-yes
-yes- can be fatal
-recurrent episodes of fever
*mosquito(the vector) bites infected person
*malaria pathogen passes into mosquito
*mosquito bites another person
*passes pathogen-protist into their blood vessels
-carries pathogen from person to person
-prevent mosquitos-vectors- breeding
They breed in still water eg ponds- drain still water
-mosquito nets to avoid being bitten( can also spray net w/ insecticides)
-spray insecticides at areas of still water
Job of non specific defence system
non specific defence systems- x4
-prevent pathogens entering
skin
nose
trachea+bronchi
stomach
how does skin protect against pathogensx4
skin-
-protective layer
-produce sebum(antimicrobial substance) kills bacteria
-outer layer has dead cells- hard for pathogens to penetrate
-when skins damaged- scabs over
how do: protect against pathogens
Nose
Lungs x2
-nose- hairs and mucus trap pathogens/(particles that contain pathogens) before they enter respiratory system
*if pathogens make it past nose to lungs
-trachea+ bronchi secrete mucus to trap pathogens
-trachea and bronchi lined w/ tiny cillia- waft mucus towards throat to be swallowed into stomach
how does stomach protect against pathogens
-contains hydrochloric acid- kills pathogens bfore they go into digestive system
2 main things the immune system does
- 3 functions of white blood cells
-destroys pathogens+ toxins they produce
-protects if same pathogen invades again
-phagocytosis
-antibody production
-antitoxin production
phagocytosis process x3
-wbc phagocyte detects chemicals released by pathogen
- moves to pathogen+ binds to them, engulfs pathogen
- pathogen is destroyed using enzymes
(harmless broken down product leaves phagocyte)
what are antibodies
- describe how antibodies are produced- what happens
x3
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why will 1 type of antibody not protect against all pathogens
why are antibodies useful in longrun-
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-protien molecules produced by wbc
-stick to pathogen
-evry pathogen has unique antigens on surface
-when wbc comes across foreign antigen- produce antibodies
-antibodies lock onto pathogens so they can be found and destroyed by other wbc
(-antibodies rapidly produced + carried around body to find all similar bacteria/viruses)
-antibodies are specific to that type of antigen- 1 lymphocyte will only produce antibody against a specific pathogen
-remain in blood for long time- protect if we get infected w/ same pathogen
body can make them again rapidly
what do antitoxins do
bind to toxin molecules produced by invading bacteria and prevent them from damaging cells- counteract toxins
TOBACCO MOSAIC VIRUS
-is it rare or widespread
-what species of plant does it affect
-what does tmv cause
-what is the effect of this
-widespread
-many species incl. tomatoes
-distinct mosaic pattern of discoloration on leaves
-rate of photosynthesis reduced so growth of plant is reduced
Rose black spot
what is it caused by
-what does rose black spot cause
-what is the effect of this
-how is rose black spot spread
-how to treat rose black spot x2
fungus
-purple/black spots develop on leaves- often turn yellow and drop early
-less photosynthesis so rate of growth decreases
-spread in environment by water/ wind
-spray w/ fungicides- kill fungi
-remove+ destroy affected leaves so fungus cant spread
vaccination involves-
why is it done-
introducing small amount of dead/inactive form of pathogen into body to stimulate the wbcs to produce antibodies.
If same pathogen re enters, wbcells react quickly to produce correct antibodies- preventing infection
when white blood cells are stimulated to produce antibodies, what else happens- why is this useful
-wbc divides by mitosis
-copies of wbc remain in blood
-if pathogen re enters- the wbcells can produce correct antibody quickly-
immune system remembers the specific antibody needed for specific antigen
what is herd immunity
large amount of population vaccinated- unvaccinated ppl not likely to catch disease bcse fewer ppl can pass it on
pros of vaccine x2
-help control spread of communicable diseases
-epidemics can be prevented if large amount of pop are vaccinated
cons of vaccines x2
-dont always work- give immunity
-sometimes you can have a bad reaction (eg swelling/fever) -but this is rare
-what do painkillers and other drugs do
-what are antibiotics+what do they do
-why don’t antibiotics or other drugs kill viruses
treat symptoms of disease (by relieving pain) but don’t kill pathogens
-medicines that help cure bacterial disease by killing infective bacteria inside body
-viruses live + reproduce inside body cells- hard to develop drugs that kill viruses w/out damaging body tissue
-what is penicillin
-why is the emergence of antibiotc resistant strains a concern
-important thing to remember when prescribing antibiotics for bacterial disease
-pro of antibiotics
-first antibiotic discovered
-in future bacterial diseases will become hard to treat
-specific bacteria treated with specific antibiotics
-greatly reduced deaths from infectious bacterial diseases
how do lymphocytes from antibodies help kill pathpogen
- 3 ways
-what are B-lymphocytes
1- cause reactions where enzymes split open pathogen cell membrane
2- makes it easier for phagocytes to find pathogen
3-makes pathogens stick together- easier for phagocytosis
- wbc that produce antibodies
-what happens once the body figures out which type of antibody is needed
how does this cause immunity
–5 points.
-memory cells-specific copies of the lymphocyte needed are produced when
the white blood cell divide by mitosis
-copies / memory cell stay in blood for decades
-If pathogen enters body again, body can immediately produce needed antibodies
-you won’t get sick from the pathogen a second time
-this is immunity
plants produce chemicals to defend themselves, we use these chemicals as drugs
-what is the heart drug- where is it extracted from
-what is the painkiller that is extracted from a tree
-what antibiotic was discovered by alexander fleming and where was it extracted from
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-heart drug digitalis extracted from foxgloves
-painkiller aspirin extracted from willow tree (used to lower fever)
-penicillin extracted from microorganism , discovered in the penicillium mould
describe how fleming discovered penicillin
he was clearing out petri dishes containing bacteria
-noticed one dish had mould on it and area around mould was free of bacteria
-that mould was producing penicillin - which killed bacteria
how are most drugs made
3 main stages of drug testing
3 things that are tested for
most drugs synthesised by chemists in pharmaceutical industry- starting point may be a chemical extracted from a plant
-preclinical-tested on human cells and tissues
-next preclinical step- test on live animals
-clinical test on human volunteers
-toxicity- if its safe for humans
-efficacy- if it treats the disease/ has effect you want
-dosage- concentration given and how often
described what happens in preclinical
-what are the guidelines for animal testing
-downsides x2
-tested IN LAB on cells/ tissues-
-AND live animals to test efficacy,dose,toxicity
- new drug must be tested on 2 different live mammals
-down side is can’t use tissues/cells to test drug that affects whole body/ many systems
-ppl think its cruel to animal test- others think safest way to make sure drug isn’t dangerous
(some ppl think animal so different to human- pointless to animal test)
clinical testing happens if…
1-First stage of clinical testing
2- If drug is successful in first stage
3-stage
what is optimum dose
drug passes preclinical animal test
-very LOW doses given to HEALTHY volunteers to check drug is SAFE on normal working body.
-amount gradually increased-
-if drug found to be safe, clinical testing continues to find optimum dose
- test on ppl w/ illness
-double blind trial (or blind) with a placebo
-optimum dose- dose that’s most effective with fewest side effects
what is a placebo-
-why is a placebo given
how does a double blind trial work
-pro of double blind trial
a substance that’s like the drug eg tablet/injection with no active drug in it- has no effect
-so can find out actual difference the drug makes- allows for the placebo effect- patient expects treatment to work so feel better
-patients put randomly in 2 groups.
-one given new drug
-other given placebo
-patient and doc X know which is placebo
-Stop bias-doctors monitoring patients and analysing results aren’t subconsciously influenced by knowledge + X pay more attention to ppl getting real drug
what’s peer review
why are results from double blind trials only published after peer review
other scientists check that the work is valid and carried out rigorously
- prevent false claims
How can bacteria become resistant
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common strain of antibiotic resistant bacteria-
how to reduce chance of antibiotic resistance- x3
problem with developing new antibiotics
-a mutation can make a bacterium resistant
-the antibiotic kills all Xresistant strains, NOT the resistant bacteria
-the resistant strain of bacteria survives and reproduces w/ no competition.
-population of resistant strain increases- natural selection
-resistant strain spreads- ppl not immune + no effective treatment
-MRSA- (resistant to strong meticillin antibiotic)
-not over-prescribe antibiotics or prescribe them for a virus
-patients complete FULL course- so all bacteria killed- none survive to mutate into resistant strains
-restrict use of antibiotics in farming- usually used to prevent animals developing bacterial disease
-timely
-costly
-antibiotic resistant bacteria constantly emerge- hard to keep up
lymphocytes produce antibodies against….
-how are monoclonal antibodies made -6 points
anything the body detects as foreign(an antigen)
-inject mouse with chosen antigen- mouse lymphocytes stimulated to produce particular antibodies
-collect lymphocytes and combine with/fuse with tumour cell
-This hybridoma cell can divide by mitosis and produce antibodies
-select single hybridoma cell(producing the antibody we want) and allow to divide/clone to produce many identical hybridoma cells
-These cells all produce the same antibodies- we call these antibodies monoclonal antibodies
-large amount of monoclonal antibodies collected and purified
-monoclonal antibodies are created from…
-the monoclonal antibodies are specific to ….
-the benefit of this is that monoclonal antibodies
why are the lymphocytes fused with a tumour cell
a single clone of hybridoma cells (lots of clones of a single wbc)
-one binding site on one protien antigen
-target a specific chemical / specific cells in the body
- the lymphocytes will X divide by mitosis but produce antibody
-tumour cell divide by mitosis rapidly but X produce antibody
4 uses of monoclonal antibodies
can they be produced against any type of antigen-
-diagnosis- pregnancy tests
- in labs- measure level of substances in blood/ detect pathogens
-in research- locate/ identify molecules in cell/tissue using fluorescent dye
-treat some diseases-eg cancer by binding to radioactive substance/drug
yes
what hormone is found in preg women urine-
- 2 parts of pregnancy test
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what happens if preg woman wees on pregnancy test - 5 points
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why do most pregnancy tests have 2 blue lines for a positive result
-Hormone HCG produced by placenta of fetus
-only found in preg womens urine
-2 parts-
#1- where u wee- has blue beads attached to monoclonal antibodies specific to HCG
#2 - test strip- has monoclonal antibodies specific to HCG that are FIXED to test strip- they bind to HCG
-if preg woman wees-
-HCG binds to antibodies on blue beads
- when blue beads flow over test strip, the HGC they are carrying binds to the fixed antibodies
- blue beads also get stuck in place
-by trapping loads of beads- strip looks blue- positive test
-second line acts as a control
-normally need two for a positive result
what happens if non preg woman wees on pregnancy test
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pros of a pregnancy test x3
-urine washes beads w/ the attached antibodies over fixed antibodies on other end
-nothing to stick the blue beads onto the test strip
-cheap
-easy to use
-highly accurate
How are monoclonal antibodies used in labs
-pro of using them in these cases
-measure level of hormones / chemicals in blood-(eg person lacks energy-may have low level of certain hormones)
-detect pathogens in blood- eg a virus
-completely specific to what we are looking for
-what are monoclonal antibodies used for in research
-describe how monoclonal antibody used in that way - 4 3 points
-to locate/ identify specific molecules in a cell/ tissue by binding to fluorescent dye
-monoclonal antibody made that binds to molecules you’re looking for
-antibodies bound to fluorescent dye
-if those molecules are present, antibodies will attach to them, we can see the location using the dye
how are monoclonal antibodies used to treat diseases - 4 points
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-advantage of this
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how do cancer cells grow
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-how are the antibodies delivered to the patient
(-cancer cells have antigens on cell membranes called Tumour markers(not found on normal bodycells))
-monoclonal antibodies specific to cancer cells (that bind to the tumour markers) are made
-monoclonal antibodies bound to either: (anti-cancer drugs)
radioactive substance,
toxic drug,
toxic chemical
-antibody attaches to cancer cells and chemical/drug stops cells growing and dividing
-delivers drug to cancer cell w/out harming other cells in body (bcse the antibodies only bind to the tumour markers)
-cancer cells undergo uncontrolled mitosis and spread around body
- through a drip
problems w/ monoclonal antibodies
- pro of using monoclonal antibodies to treat cancer instead of chemo/radio therapy
-create more side effects than originally expected
*fever
*vomiting
*low blood pressure
-in certain drug trials they caused very harmful side effects
-so not as widely used as everyone hoped when first developed
-they can affect normal body cells as well as kill cancers
monoclonal antibodies target specific cells-
-side effect of an antibody based drug lower than chemo/radio therapy
how can you detect plant diseases x7
-stunted growth
-growths
-areas of decay
-spots on leaves
-discolouration
-pests
-Mallformed leaves/stems
-how can identification be made x3
-reference to gardening manual/ website
-take infected plant to lab to identify pathogen
-using testing kits that contain monoclonal antibodies
-what do aphids do
-what is the effect
-are insects pathogens
-extract nutrients eg sugars from plant
- cause stunted growth
-no, X cause infectious disease
what 2 ions do plants need- why
-what can a lack of either do
The understanding of ion deficiencies allows…..
-nitrates
-needed in protien synthesis (to make protiens)
therefore for growth
LACK= stunted growth
-magnesium
-needed for making chlorophyll
needed for photosynthesis
LACK= chlorosis - lose green colour- yellow leaves
-horticulturists to provide optimum conditions for plants
3 types of plant responses
*physical defense responses
- resist invasion of microorganisms
*chemical defense responses
*mechanical adaptations
3 physical plant defence responses
-cellulose cell wall
*physical barrier difficult for microorganisms to penetrate
-tough waxy cuticle
*barrier-difficult for microorganism to penetrate- protect from attack
-layers of dead cells around stems (bark on trees) which falls off
*barrier of entry to microorganisms
3 mechanical adaptations
-Thorns and hairs to deter animals
*Thorns directly protect plant from being eaten
*hairs irritate mouth of herbivore- hard to eat
-leaves which droop/ curl when touched
*prevent themselves being eaten- knock off insects /move away
*scare herbivores- not used to plants that move
-Mimicry to trick animals
*Tricks animal into not eating them
- dead white nettle looks like stinging nettle
-passion flower has spots- looks like butterfly eggs- stops others laying eggs
-some look like rocks/ pebbles
2 chemical plant defence responses
- antibacterial chemicals
*kill bacteria- prevent them attacking plant -eg mint/witch hazel
-poisons to deter herbivores
*from grazing on plant - eg tobacco plants,fox glove, night shade
