b6 Flashcards
how do vaccines work?
inject small amount of dead or inactive pathogens which have antigens. these cause the body to produce antibodies to attach to them. (triggers an immune response)
the antibodies produced are stored as memory cells, so when infected, body can produce those antibodies much quicker
pros of vaccines
- help control lots of communicable diseases that were once very common - polio, measles
- big outbreaks (epidemics) can be prevented if a large percentage of the population is vaccinated. fewer people can pass on the disease so fewer can catch it. (herd immunity)
cons of vaccination
they do not always work - do not always give immunity
could sometimes have a bad reaction to the vaccine
antibiotics
treat bacterial disease by stopping bacteria cellular processes so do not work against viruses as they reprodice inside cells - the cause of the disease
painkillers
treat the symptoms of the disease, not the disease
why is it difficult to treat viral diseases?
viruses reporduce inside cells so killing viruses would also cause harm to body cells
ways to prevent resistant bacteria
- avoid overuse of antibiotics
- do not use antibiotics in non-serious infections
- do not use for viruses
- patients should finish whole course of antibiotics so that all bacteria are killed and none are left to mutate to resistant strains
- reduce agricultural use of antibiotics
how to reduce spread of resistant strains
- good hygiene practices like hand washing and sanitisers
- isolation of infected patients
where does digitalis come from
foxgloves - its a heart drug (strengthens heart beat)
where does aspirin come from
willow bark and is a pain killer
where does penicillin come from
penicillium mould, alexander flemming. is an antibiotic
what are drugs tested for?
toxicity, efficacy, dosage
preclinical testing
in a lab using cells, tissues, and live animals
clinical trials
uses healthy volunteers, then patients
- low does of the drug are given at start of trial
- if drug is safe, further clinical trials are carried out for optimum dose of drug
- can be double blind and iven placebos
why are placebos used
to remove the psychological effect of the drug. it is a medicine that does not contain the active drug being tested
what are monoclonal antibodies
made by identical immune cells which are clones of the parent cell
the antibodies are specific to one binding site on one protein antigen and so are able to target a specific chemical or specific cells in the body
how are monoclonal antibodies produced?
- stimulating mouse lymphocytes to make a
particular antibody. - the lymphocytes are combined with a particular kind of tumour cell to make a cell called a hybridoma cell.
- the hybridoma cell can both divide and make the antibody.
- single hybridoma cells are cloned to produce many identical cells that all produce the same antibody.
- a large amount of the antibody can be collected and purified.
uses of monoclonal antibodies
- for diagnosis like pregnancy tests
- in labs to measure hormone levels/chemicals in blood/ pathogens
- in research to locate/identify specific molecules in cell or tissue by binding with fluorescent dye
- to treat some diseases
how monoclonal antibodies used to treat cancer
monoclonal antibody is bound to radioactive substance/toxic drug/chemical which stops cells growing and dividing.
it delivers the substance to the cancer cells without harming other cells in the body.
disadvantages of monoclonal antibodies
- cause more side effects than first expected
- expensive
- more difficult than expected
symptoms of plant disease
- stunted growth
- spots on leaves
- areas of decay
- growths
- malformed stems or leaves
- discolouration
- presence of pests
how are plant diseases identified?
- reference to gardening manual or website
- taking infected plants to lab to identify pathogen
- using testing kits that contain monoclonal antibodies
nitrate deficiency in plants
stunted growth as nitrate ions are needed for protein synthesis
magnesium deficiency in plants
chlorosis as magnesium ions are needed to make chlorophyll
physical defence responses in plants
- cellulose cell walls
- tough waxy cuticle on leaves
- layers of dead cells around stem which fall off (bark)
chemical defence responses in plants
- antibacterial chemicals
- poisons to deter herbivores
mechanical adaptations in plants
- thorns and hair deter animals
- leaves which droop or curl when touched
- mimicry to trick animals
why can monoclonal antibodies not be consumed oraly
they are proteins so would be broken down into amino acids by protease
why has there been an increase in resistant strains of bacteria
- there are less non resistant strains as they have been killed by antibiotics so there is less competition
- theres been an overuse of antibiotics / antibiotics have been prescribed for mild infections
