Infection & Response Flashcards
three ways diseases are spread
direct contact
water
air (droplet infection)
Majority of diseases are from…
bacteria or viruses
Bacteria- larger than?, do what rapidly?, release what?
larger than viruses, reproduce rapidly, release toxins which damage tissues + make us feel ill
Viruses- smaller than what?, live where?, reproduce rapidly using…, what do they do to host’s cells
smaller than bacteria, live inside body cells, reproduce rapidly using host’s body cells, damage and eventually destroy host’s cells, burst out + infect more cells
reduce the spread of disease by doing 4 things
- simple hygiene measure (storing meat safely etc)
- destroying vectors
- isolating innfected individuals
- vaccinations
Viral diseases- what would happen if we tried to destroy them, what do we do instead
viruses live in body cells so if we tried destroying them it would destroy the the cells too, so we prevent disease instead
HIV (viral)
spread- sexual contact/ exchange of bodily fluids
symptoms- flu-like
treatment/prevention- if caught early= antiretrovirals, if not it can turn into AIDS + immune system damages so prevention by not sharing needles/ using condoms
TMV (viral)
spread- direct contact + vectors
symptoms- gives leaves mosaic pattern + discolouration= less photosynthesis + less growth
treatment/prevention- pest control
Salmonella (bacterial)
spread- under-cooked meat eaten/ food prepared in unhygenic conditions
symptoms- fever, vomiting, abdominal cramps, diarrhoea
treatment/prevention- poultry vaccinated, practice safe food hygiene
Gonnorrhoea (bacterial)
spread- sexual contact
symptoms- thick yellow/green discharge from penis/ vagina, pain upon urinating
treatment/prevention-penecillin (antibiotic), but there are some resistant strains, use condoms
rose black spot (fungal)
spread- spores spread by wind and water
symptoms- purple/black spots, turn yellow, fall off early,less chlorophyll so less photosynthesis so less growth
treatment/prevention- chemical fungicides, removing + burning infected leaves
Malaria (protist)
spread- mosquito vecotr
symptoms- circulates around body damaging blood cells + liver cells, fever, can be fatal
treatment/prevention-mosquito nets, drain standing bodies of water= reduces breeding ground, insecticides
4 things in human first line of defense
- nose hairs
- skin-produces antimicrobial secretions, covered with microorganisms
- trachea + bronchi- produce mucus + has cilia
- stomach has HCL to kill most pathogens
second line of defense- three things
- phagocytosis- engulfs + digests pathogen
- antibody-pathogens have antigens, antibodies attach to this which tells phagocytes to come and engulf
- antitoxins- neutralise toxins from oathogen
How vaccinations work
- small amount of dead/ inactive pathogen put in vaccine
- lymphocytes produce antibodies slowly
- next time you come into contact with that pathogen, memory cells multiply and quickly make more antibodies before symptoms show
herd immunity def
when the majority of people in a group are vaccinated preventing the spread of diseases even to those who aren’t vaccinated
antibiotics- cures what, without doing what, example, what is an issue, what can’t they kill
cures bacterial diseases
without harming your cells
e.g penecillin
specific antibiotics work against specific bacteria
some strains have developed antibiotic resistance
can’t kill viruses
Painkillers only…
only soothe symptoms
3 drugs that are needed to know + what they originate from + history behind the important one
- heart drug digitalis- fox gloves
- painkiller aspirin- willow trees
- antibiotic penecillin- penicillium (mould), Alexander Fleming accidently discovered it when he left bacteria cultures open, the ones with mould growing had clear rings around the mould= it killed the mould
now drugs are… but starting point may still be a…
now drugs are synthesised but starting point may sitll be a chemical from a plant
drugs are tested for…
stages of testing
toxicity, efficacy, dosage
preclinical testing- done in a lab with cells, tissues, whole organs and live animals
clinical trials- first low doses to healthy volunteers, then to small group patients, then large group of patients
results are only published after…
peer review
Monoclonal Antibodies- how are they made
- mouse injected with antigen so lymphocytes produce antibodies
- lymphocytes are then combines with tumour cell to make hybridoma
- hybridoma can produce antibodies + can divide rapidly
- a single hybridoma cell is clones to produce many identical cells
- a large amount of the antibody can be collected + purified for use
4 uses of monoclonal antibodies
- Pregenancy tests- HCG made if pregnant, so MABs will bind to it which causes a colour change
- MABs can be bound to flourescent dye, they are used in research to locate/ identify specific molecules/ cells
- MABs can be used to detect disease by binding to pathogen’s antigens or by binding to hormones/ chemicals made in high amounts
- MABs can treat some diseases e.g. cancer by binding to a toxic drug, radioactive or chemical that stops all growing, so when MAB binds to cell it delivers the substance without damaging healthy cells
disadvantage to using monoclonal antibodies
because they are made from mouse lymphocytes, there are side effects so are not very widely used
Plant diseases- Insects
aphids have sharp mouthpieces to penetrate the phloem and suck out the sap, this reduces growth, they can be destroyed by chemical or biological (predator) pesticides
Nitrate deficiency- whats it needed for + what happens if there isn’t enough
needed for protein synthesis + growth, so stunts growth
Magnesium deficiency- whats it needed for + what happens if there isn’t enough
used to make chlorophyll, so gives yellow colour + reduces growth
7 signs of diseased plants
- discolouration
- presence of pests
- spots on leaves
- areas of decay
- malformed leaves/stems
- growths
- stunted growth
how to identify what disease a plant has- 3 ways
- use gardening manual/ website
- samples in lab to identify pathogen
- testing kits containing monoclonal antibodies
Physical plant defences- 3 things
- cellulose cell wall- hard for pathogens to enter
- tough waxy cuticle- barrier
- thick bark + plants can have layer of dead cells around the stem- protects
Chemical plant defences- 2 things
- produce anti-microbial chemicals- protects from pathogens
- produce poisons- deters herbivores from eating
Mechanical plant defences- 3 things
- hairs/ thorns- deters herbivores from eating
- mimicry- plant copies something to look off-putting
- drooping leaves upon touch- scares animals
