Infection And Responce Flashcards
what are pathogens
microorganisms that enter the body and cause disease
bacteria and their effect on the body
1/100th size of body cell
reproduce rapidly
make u feel ill by producing toxins that damage cells
viruses and their effect on the body
1/100th size of bacterium
not cells
can reproduce rapidly
live inside cells
replicate themselves using cells machinery
the cell then bursts releasing new viruses
cell damage make u feel ill
protists and their effect on the body
eukaryotes and mostly single celled
some are parasites
live on or inside other organisms
often transferred by vectors
fungi and the effect on the body
some single celled
others have body made of hyphae
hyphae grow and penetrate human skin
hyphae produce spores which can be spread to other organisms
what are the ways pathogens can be spread
water
air
direct contact
vectors
measles
viral spread through droplets in sneeze or cough red skin rash and fever can be fatal e.g lead to pneumonia most people vaccinated
HIV
virus spread through sexual contact and sharing needles flu like symptoms usually doesn't experience symptoms for several years controlled by antiretroviral drug virus attacks immune cells then cant fight off other disease know as aids at this point
tobacco mosaic virus
affects plants
mosaic pattern on leaves and discolouration
this means plant cant photosynthesize
so virus effects growth
rose black spot
fungus purple or black spots then turn yellow and drop off less photosynthesis spreads through water and wind treated with fungicides and stripping plant of effected areas
malaria
caused by protist
vectored by mosquito
pick it up when feeding on infected animal
repeating episodes of fever
stopped by preventing mosquitoes from breeding by removing water where they breed
sleeping under mosquito nets
salmonella
bacteria fever, stomach cramps, vomiting diarrhoea caused by toxins bacteria produce food prepared in unhygienic condition eating contaminated chickebn
gonorrhoea
std unprotected sex bacteria pain urinating thick yellow or green discharge penicillin resistant other antibiotics condoms
how can diseases be stopped from spreading
hygiene
destroying vectors
isolating infected individuals
vaccination
what are the bodies non specific defence systems
skin- secretes antimicrobial substances
hairs and mucus in nose trap particles
trachea and bronchi secrete mucus
stomach produces hci
explain phagocytosis
white blood cells engulf foreign cells and digest them
why do white blood cells produce antitoxins
to counteract toxins produced by invading bacteria
how do antibodies fight pathogens
pathogens have antigens of their surface
when white blood cells fin them they produce antibodies
which are proteins which lock onto the antigens
antibodies are specific to each antigen
if person is infected with same pathogen again, antibodies can rapidly be produced
how do vaccines work
injecting small amounts of deaf or inactive pathogens
they carry antigens which make ur white blood cells produce antibodies to attack them
so if real pathogens enter u can rapidaly produce antibodies
pros of vaccination
diseases that used to be a lot are now little. e.g. polio
epidemics can be prevented
ppl who are not vaccinated are less likely to get it cus there are less people to pass it on
cons of vaccination
dont always work can be worse than disease itself can suffer long team side effects allergic reactions may not have got disease anyway expensive
what are pain killers
drugs that relieve pain
dont tackle disease
just reduce symptoms
what are antibiotics
kill or prevent the growth of Bactria
different antibiotics kill different bacteria
dont destroy viruses
antibiotic resistant bacteria
only non resistant strains are killed when using antibiotics
resistant strain will survive and reproduce
so population increases
and can cause serious infection
the bacteria has mutated
how do you slow down the development of antibiotic resistance
avoid over prescribing antibiotics
finish whole course of antibiotics
how do plants relate to the origins of drugs
plants priduce chemicals to defend themselfs
theses chemicals can be used as drugs
for exapmle aspirin came from willow and is a piankiller
how was penicillin discovered
fleming nticed mould on bacertia in petri dish and the area around it was clear of bacteria
what percentage of drugs are plant based
11
why do drugs have to be tested
to make sure they are safe, effective and to get the right dosage
what is the first stage of preclinical trials
drugs tested on human cells and tissues, however cannot see what drug does rto whole or multiple body systems
last stage of pre clinical trials
animals to test efficiency and toxicity
law says must be tested on 2 different live mammals
what happens in clinical trials
tested on healthy volunteers at low dosage
then on people suffering from illness
optimum dosage is found
whats the point in placebos
ppl put in 2 groups where one is given drug and other a placebo. so doctor can see actual difference drug can make
what is a double blind trial
neither patient or doctor knows before results have been collected
why use a double blind trial
so no results are subconsciously influenced
what went wrong with thalidomide
effective at relieving morning sickness in pregnant women but hadnt been tested for this use.. it passes through placenta and causes abnormal lib development in the foetuses
how are monoclonal antibodies made
produced in B- lymphocytes ( a type of white blood cell)
- mouse is injected with chosen antigen
- B-lymphocytes taken from mouse
- fused w tumour cell made in lab
- this makes a hybridoma
- which divides quickly to produce lots of clones that produce monoclonal antibodies
how do pregnancy tests work
the bit u wee on has antibodies on it which attach to a hormone with blue beads. the teststrip has more antibodies stuck onto it so if u have HCG in ur wee it will turn blue. this is as the urine oves up the stick carrying the hormone and beads wich bind to the antibodiy on the stip so they get stuck.
what are the antigens on cancer cells called
tumour markers
how are monoclonal antibodies used to treat cancer
monoclonal antibodies are made in a lab which bind the the tumour markers of cancer cells. anticancer drugs can be attached to the antibodiy. the antibody targets the cancer cells and binds to them and then the drug can kill the cancer
what 2 ways can monoclonal antibodies be used in labs
measure the levels of hormones and chemicals in the blood by binding to them
test blood samples for certain pathogens
how can monoclonal antibodies be used to locate molecules on a cell or tissue
made to bind to molicule u r looking 4
then bound to fluorescent dye
what does a lack of nitrates cause in plants
stunted growth
what is chlorosis
plants get yellow leaves and stunted growth as they dont have enough chlorophyll due to a deficiency in magnesium ions
what are 6 common signs of plant disease
stunted growth spots on leaves patches of decay abnormal growth malformed stems and leaves discolouration
how can specific plant diseases be identified
looking up sighs in gardening manual
taking plant to a lab
using testing kits
plant physical defences
waxy cuticle to stop pathogens entering
cell wall if pathogens make it past waxy cuticle
layers of dead cell around their stems
plant chemical defences
antibacterial chemicals which kill bacteria
poisons to deter herbivores
plant mechanical defences
thorns and hairs
leaves that drop or cuel
mimic things to look like stones or look like they have already has eggs laid on them
