B3 Flashcards
what kind of diseases are measles and HIV
viral, human disease
how do measles spread?
through airborne droplets and direct contact
what are the main symptoms of measles?
distinctive rash and fever
How can you control the spread of measles
isolate infected people and vaccinations
how can you treat measles?
you can’t treat the virus but can treat symptoms with painkiller
How is HIV transmitted?
is transmitted through bodily fluids, sharing needles and unprotected sex
how can you prevent HIV?
sterilise needles and only use them once, use a condom
does HIV have a cure?
No, infected people are given antiretoviral drugs to slow down the development of HIV into AIDs
How does HIV turn into AIDs?
- you feel flu - like symptoms which disappear
- so you may not know that you have been infected
- months or years later the virus becomes active again but is then known as AIDs
What happens when you get AIDs
Yout immune system has been attacked and it is then difficult to fight off infection
what does TMV stand for? How does TMV spread?
Tobacco Mosaic Virus
it spreads by contact between plants naturally or by farmers hands
What happens when to a plant that has TMV?
the chloroplast of the plant is infected —> meaning it no longer absorbs light for photosynthesis
TMV: what colour do the leaves change to
green and then develops a mosaic pattern
is there a cure for TMV?
NO, tools are cleaned and infected plants are removed
What type of infection are salmonella and gonorrhoea
bacterial infection
What causes salmonella
bacteria that causes food poisoning, found in under-cooked food or food that isn’t heated properly
how to prevent salmonella?
cook food properly and in hygienic conditions
what is salmonella treated with?
antibiotics, symptoms don’t last long so body fights of infection within few days
what is gonorrhoea?
a sexually transmitted disease
What does gonorrhoea cause?
-causes burning pain when urinating
-can from thick yellow discharge
- if untreated can cause infertility
are antibiotics used to treat viral or bacterial infections? why?
bacterial , because viruses are inside cells and can’t be reached
What type of infection are rose black spots?
fungal infection
how are rose black spots spread?
by water, wind or touch ( gardeners hand)
how to prevent rose black spot
take out leaf or whole plant that is infected, sterilise gardening tools
what treatment is used for rose black spots?
spraying fungicides
How do rose black spots reduce the growth of a plant?
they reduce the volume of chlorophyll in leaves —> so less light is being absorbed for photosynthesis
what kind of infection is malaria?
protist infection
how is malaria spread?
by mosquitos who carry the protist
what are the symptoms of malaria?
fever, sweat, liver damage
how can you control the spread of malaria? (4)
mosquito nets, insect repellent, drain stagnant water ( they lay their eggs there), insecticides ( used to clean crops)
how do you treat malaria
anti- malarial drugs to treat symptoms and prevent infection
What is a vector?
an organism that spreads diseases but not affected
list ways pathogens can spread
1.food and water
2. insect bites
3. airbourne droplets
4. indirect contact
5. direct contact
list ways to prevent pathogens from spreading
- wash hands
- clean drinking water
- use condom
- isolate infected people
- vaccinations
what is a pathogen?
microorganisms that cause infectious diseases
what are examples of pathogens?
bacteria, viruses, fungi, protists
what happens to bacteria once inside cell?
reproduces rapidly and releases toxins
what do toxins do?
damage tissues, making us feel ill
Can viruses reproduce?
can’t reproduce by themselves can only reproduce inside a host cell
What are the functions of the immune system?
- destroys pathogens and any toxins they produce
- protects us incase the same type of pathogen invades again
explain how WBCs destroys pathogens (phagocytosis)
- detects chemicals released from the pathogen and moves towards it
- then ingests the pathogen
- then uses enzymes to destroy the pathogen
what are antibodies?
protein molecules produced by WBCs
how do antibodies kill pathogens
- the antibodies stick to the pathogens
- this triggers the pathogens to be destroyed
what do antibodies have to be?
specific
what produces antitoxins
white blood cells
what prevents toxins from damaging cells and how?
antitoxins stick the toxin molecules preventing them from damaging the cells
What do vaccines involve?
involves introducing small quantities of dead or inactive forms of pathogens into the body
can these dead or inactive forms of pathogens lead to disease in patients?
no, because its’s dead and inactive
how do WBCs divide?
by mitosis to produce copies of itself
what is herd immunity?
when an unvaccinated person can’t be infected because everyone around them has been vaccinated so they can’t spread a pathogen to them
can antibiotics kill viruses?
no, they kill the infective bacteria inside the human body without harming body cells
what is the 1st antibiotic?
Pencillin
what is antibiotic resistance?
- when certain antibiotics are not effective because they have been overused
- when the bacteria has evolved so no longer killed by antibiotics
what do painkillers do?
treat symptoms of diseases by relieving pain
- they don’t kill the pathogen
where do most drugs come from?
plant extracts
what do foxgloves contains?
an active ingredient for a drug called digitails
what is digitail used to treat?
heart arrhythmia ( when you have an abnormal heart beat
where does the painkiller aspirin originate from?
the plant/ tree willow
who discovered penicillin?
Alexander Fleming
what was penicillin discovered from?
penicillium mould
where can drugs be extracted from?
microorganisms
Steps for drug development (3)
- starts with chemist designing a molecule
- then tested in lab to see if it is toxic
- tested on live animals to find the correct dose
when will a drug face clinical trials?
when it passes the animal testing stage
what are the 3 phases for clinical trials?
phase 1: carried out on healthy people
- checking safety of drug and side effects
Phase 2: carried out on a small group of patients
- where scientists see if drug is effective
Phase 3: large scale clinical trial (placebo included)
- find optimum dose
- healthy/ effective for wide range of people (young, old)
what happens after all 3 phases of clinical trial
drug company submits research to government to ask for license to sell the drug
what is efficacy?
how effective the drug is
what is placebo
a fake drug/ a dummy treatment
what is double blind trial?
when neither the doctors nor the patients know who has the real drug and who has the placebo
what is the reason for a double blind trial?
- to prevent bias
- so the efficacy of the drug can be seen
why is a computer simulation used when developing a new drug?
to see if the drug will interact with the target
why is the drug tested on cell cultures?
to test the toxicity/ make sure it isn’t toxic
what is thalidomide?
a drug taken to help people sleep
what happened during the development/ trials of thalidomide?
- said to be completely safe when tested on animals –> because they couldn’t find a dose high enough to kill a rat
- was then prescribed to pregnant women –> as a cure for morning sickness
- these women’s babies were born with birth defects
how long do preclinical trials take to be completed?
12 months
how long do clinical trials take to complete?
7 years
how long will it take for a drug to be on the market?
8 years
