Infection + Response Flashcards
what is a vector?
a carrier of a parasite, but is not infected by it
what are communicable diseases?
diseases which are spread between organisms
what is a pathogen?
microorganism which causes disease
what is a host/
organism which carries disease inside its cells
what is an antibody?
Y-shaped specialised protein molecule which have binding sites specific to particular antigens. When antibodies bind to antigens, the pathogen is ineffective/neutralised - not killed
describe the anatomy of bacterial cells.
nucleoid (DNA), plasmids, ribosomes, cytoplasm, capsule, cell wall, cell membrane, flagellum
describe the anatomy of a virus
protein molecules, capsid, DNA or RNA (nucleic acid), envelope protein
what are some symptoms of salmonella?
Fever, stomach cramps, diarrhoea, nausea, vomiting, chills, headache
what are some causes of salmonella?
Eating food contaminated with animal faeces, Contact with infected animals, touching contaminated Door handles
how can salmonella be treated and prevented?
- Separating raw meat and poultry from produce, Washing hands/boards/cutlery/utensils/fruit&veg
- Antibiotics, Drink extra fluids
what are some symptoms of gonorrhoea?
Pain, discomfort, bleeding outside of periods, unusual discharge
what are some symptoms of HIV?
Fever, fatigue, swollen lymph nodes, diarrhoea, weight loss, pneumonia
what are some symptoms of measles?
High fever, cough, runny nose, watery eyes, rash
what are some symptoms of rose black spot?
purplish/black spots on upper leaf surface, Yellow leaves, Dropping leaves
what are some symptoms of malaria?
fever, chills, headache, nausea, muscle aches, anaemia, jaundice
what are some causes of gonorrhoea?
Infected bodily fluids during intercourse
what are some causes of HIV?
sexual contact with infected partner, blood contamination
what are some causes of measles?
Coughing, sneezing - direct contact with nasal or throat secretions
what are some causes of rose black spot?
Spores in wind/water
how can gonorrhoea be treated and prevented?
antibiotic injection, condoms
how can HIV be treated and prevented?
Antiretroviral therapy, Condoms, Not sharing needles, Preventative medicines, Limit sexual partners
how can measles be treated and prevented?
Painkillers, Vaccination, Wash hands, Use tissues
how can rose black spot be treated and prevented?
Fungicides, removing/destroying infected leaves, Not planting roses too close together
how can malaria be treated and prevented?
Long sleeved clothing, mosquito nets, Covering water sources, Spray water sources with insecticide, Preventative medicine
describe the life cycle of malaria.
- Person is bitten and saliva is injected into person
- Parasites travel through blood stream to liver where they reproduce rapidly
- Every 4-5 days burst out of liver cells, destroying them
- infect new cells
- Cycle repeats
describe the function of skin in preventing disease.
- acts as a Barrier to prevent pathogens entering body
- produces sweat, epithelial cells, scabs, blood clots,
- it Sheds and is waterproof
- has Specialised immune cells in skin tissue
- Secretion of sebum (anti-microbial)
how can pathogens can enter the body via the skin?
- Cuts in skin
- Bites
- contact/absorption
describe the function of nose in preventing disease.
- Stops pathogens entering body, traps & ejects them
- Ciliated cells, Mucus, Sneezing, Hairs
how can pathogens can enter the body via the nose?
breathing them in
describe the function of trachea/bronchi in preventing disease.
- Catch & eject pathogens to stop them entering body
- Cilia, Coughing
describe the function of the stomach in preventing disease.
HCl acid kills pathogens
describe the function of eyes in preventing disease.
- Barrier and removal method for pathogens
- Tears contain lysozyme which damages bacterial cells
- Eyelashes
describe the defence mechanisms of reproductive organs in preventing disease
- Physical barrier - epithelial cells
- Uterus lined with acid
- Secretion of bodily fluids with antibacterial agent
describe the defence mechanisms of mouth in preventing disease
- Saliva contains antibodies - also washes bacteria into stomach & then vomit
- Oral mucosa
describe the process of vaccination
- a Weakened or dead form of pathogen which cannot cause serious disease is injected into body
- Phagocytes engulf pathogen and display the antigens on surface of cells
- Phagocytes go to lymph glands and locate B-cells which recognise the antigens
- B-cells cloned by mitosis and produce antibodies which they send into blood stream
- Antibodies immobilise antigens so the pathogen cannot infect any more human cells
- B-cells become memory cells so that if the body is exposed to the actual pathogen, will recognise pathogen immediately, producing antibodies rapidly in large numbers so no symptoms occur
what is different in the 2nd exposure to a disease?
- More antibodies because there are more T & B cells as memory cells, so more antibodies can be produced
- Antibodies made faster because memory cells remember pathogen antigens and do not have to locate T & B cells and there are more T & B cells to produce antibodies
- Antibodies last longer because more of them are made
describe the process of phagocytosis.
- solid substances/ whole organisms brought inside cell via invagination = engulfed
- Vacuole formed - inner surface derived from outer surface of cell membrane - the membrane is the phagosome
- Bacteria destroyed by digestive enzymes
describe the function of lymphocytes.
- recognise specific antigens on invading pathogens and detect that the proteins and pathogens are foreign
- The antibodies created by the lymphocytes cause pathogens to stick together and make it easier for phagocytes to engulf them.
- Each lymphocyte produces its own specific receptor that corresponds to a specific antigen. When a lymphocyte encounters that antigen it multiplies, creating large numbers of identical lymphocytes bearing that particular receptor.
describe the function of b-cells.
- produce antibodies against antigens
- remain in organs of immune system and send antibodies to infections, which are complimentary to antigen
describe the function of t-cells.
- make antitoxins which bind to toxins produced by pathogens to prevent people from feeling ill by alleviating symptoms (ie lethargy, nausea)
- they travel from immune system organs to infection site to release complimentary antitoxins to neutralise toxins
what are antigens?
molecules, often proteins, located on the surface of cells that trigger a specific immune response.
list some of the causes of antibiotic resistance. [5]
- Using antibiotics to treat a virus
- Preventative use in farming
- Not finishing a course
- Not taking a high enough dose
- Not taking antibiotics specific to bacteria causing illness
describe how antibiotic resistance occurs
- in Normal bacteria, Random mutation occurs which makes one bacterium resistance to antibiotic
- Initially, mutation has no advantage
- If antibiotic used, unadapted die but the resistant have advantage and survive
- Resistant reproduce and pass resistance to offspring and become dominant species
give an example of an antibiotic
penicillin, methicillin, ampicillin
give an example of a painkiller
ibuprofen, paracetamol, aspirin
give an example of an antiretroviral drug
COVID, malaria
what is the function of antibiotics?
to kill bacteria
what is the function of painkillers?
reduce symptoms
what is the function of antiretroviral drugs?
destroy viruses
what is a problem with antibiotics?
resistance
what is a problem with painkillers?
can be addictive
what is a problem with antiretroviral drugs?
ineffective
what is the source and use of digitalis?
foxgloves - treating heart disease
what is the source and use of penicillin?
penicillium mould (disc. Alexander Fleming) - anitbiotic
what is the source and use of aspirin?
willow bark - painkiller
describe the process of preclinical drugs testing. [4]
- first, using donated cells to look for efficacy and toxicity
- then using donated tissues to test for efficacy and toxicity
- then use larger sample of cells to increase accuracy
- finally use live animals to test for efficacy and toxicity within a whole organism
describe the process of clinical drugs testing [2]
- first use healthy volunteers to test for toxicity and side effects - use a Low dosage
- then use ill Patients - Start small (10-50) then large no.patients (10000) - to Test for efficacy and dosage
what does a bactericidal antibiotic do?
kills/destroys bacteria
what does a bacteriostatic antibiotic do?
stops bacteria growing/reproducing
what is a double blind trial?
subject and researcher don’t know whether the drug or a placebo has been given
what is a double blind trial used for?
Eliminate researcher bias, Avoid unreliable results/Bribery, Avoid placebo effect
describe the process of producing monoclonal antibodies
- Mouse is vaccinated to start formation of antibodies
- Spleen cells that form antibodies are collected in operation
- Fused with tumour cells called myeloma cells
- Forms hybridoma cells
- Grown in lab
- those that produce antibodies are separated
- Antibodies are collected
describe how monoclonal antibodies are sued to test for pregnancy
- The person gives a urine sample. If they are pregnant, their urine should contain HCG hormone
- urine passes through reaction zone; if HCG is present, it will bind to free mobile antibodies, which have an enzyme attached to them
- urine passes to test site, carrying the HCG bound to the free antibody (and by extension the dye enzyme). Here, the HCG-free antibody complex will bind to another fixed antibody using the HCG. This will bring the enzyme (attached to the complex) close to a dye substrate – a reaction occurs, causing a colour change.
- urine passes to control site where there are fixed antibodies which will bind to any free antibody (not just those bound to HCG), and cause a colour change here.
- If a person is not pregnant, the free antibody moves through the test site, and instead binds to the fixed antibody in the control site, causing a colour change here.
- If a person is pregnant, the HCG-free antibody complex will form in the reaction site, and this complex binds in the test site, causing a colour change here. Some free antibody will still pass to the control site, so you will see two stripes.
describe how antigens are measures with monoclonal antibodies.
- Line test tube with antibodies
- Add blood
- Antigens bind to antibodies
- Add more antibodies (same as the initial ones) with enzyme attached
- If blood contains antigens, antibodies will also bind to antigens
- Rinse away anything that didnt bind
- Add substrate that causes colour change in enzymes
what are symptoms of disease in plants?
- stunted growth
- spots on leaves
- areas of decay
- unusual growths
- malformed stem/leaves
- discolouration
- presence of pests
what are the symptoms of tobacco mosaic virus?
Pattern of light & dark green on leaves, Malformed leaves, Yellow streaked leaves, Yellow veins - as there is less chlorophyll, making it harder to photosynthesise
what are some causes of tobacco mosaic virus?
- Worker’s hands/tools/clothes
- Contact with animals
- Leaves rubbing together
what is the treatment for tobacco mosaic virus?
- Destroy infected plant
- Use sterile equipment
- Rotate crops
what is the effect of a Mg deficiency in plants?
- Can’t make chlorophyll so plant cant absorb light
- cant photosynthesise so cant create glucose
- cant release energy/respire so cant survive/grow
what is the effect of a nitrates deficiency in plants?
- Nitrate + glucose -> amino acids
- Cant make proteins so cant grow
how are acacia plants adapted?
- lots of thorns to deter sensitive animals
- High crown to avoid short animals
how are nettle plants adapted for defence?
stinging hairs to deter sensitive animals
how are pebble plants adapted for defence?
mimics rocks to camouflage
how are passion flowers adapted for defence?
mimics butterfly eggs in petal pattern to stop butterflies laying their eggs there
how is bracken adapted for defence?
Poisons in leaves that cause cancer/blindness to poison herbivores
how is the mimosa plant adapted for defence?
Rapid movement to Avoid herbivores
how is the dead nettle plant adapted for defence?
looks like nettles to trick herbivores
