Infection & Response - Y10 Flashcards
What are the types of pathogens?
- Virus
- Bacteria
- Protists
- Fungi
How can the spread of diseases be reduced or prevented?
- Good hygeine
- Vaccination
- Killing vectors
Name ways pathogens can spread
- Direct contact
- Water
- Air
What does bacteria do in the body?
Produces toxins that damage tissues and makes us feel ill
What do viruses do in the body?
They reproduce inside cells, causing cell damage
What is a pathogen?
A microorganism that causes disease
What is measles, symptoms, how is it spread and how can it be prevented?
Viral disease that causes a fever and red skin rash. Spread by inhalation of droplets from sneezes and coughs. Most children are vaccinated.
What is HIV, symptoms, how is it spread and how can it be prevented?
Virus, causes flu-like illness, spread by sexual contact, sharing of needles, exchange of bodily fluids. Can be controlled with antiretroviral drugs.
What happens if HIV isn’t treated?
It causes AIDS when the body’s immune system becomes so badly damaged that it cant deal with infections.
What is TMV, how is it spread, symptoms, and how can it be prevented?
Virus, affects plants, gives a mosaic pattern of discolouration which affects growth of plant, spread by contaminated tools, prevented by sterilising tools
What is Salmonella, how is it spread, symptoms and how can it be prevented?
Bacteria (food poisoning), spread by bacteria ingested in food, poultry can be vaccinated against Salmonella, causes fever, abdominal cramps, vomiting, diarrhoea (caused by toxins they secrete)
What is gonorrhoea, how is it spread, symptoms and how can it be prevented?
Bactera (STD), thick yellow discharge, pain urinating, treated with antibiotic penicillin, spread by sexual contact, prevented by contraception
What is rose black spot, how is it spread, symptoms and how can it be prevented?
Fungal disease, causes purple/black spots that often turn yellow and drop, affects growth of plant, spread by water/wind, treated with fungicides or removing/ destroying affected leaves.
What is malaria, how is it spread, symptoms and how can it be prevented?
Protist disease - has a life cycle that includes the mosquito, causes recurrent episodes of fever, prevented with mosquito nets, destroying vector’s habitats.
Name non-specific defense systems
- Skin
- Nose
- Trachea
- Bronchi
- Stomach
- Tears
What is the role of the immune system in the defence against disease?
Protects body from pathogens
What do WBC do to defend against pathogens?
- Phagocytosis
- Antibody production
- Antitoxin production
How does vaccination prevent illness?
- Vaccine contains a small quantity of inactive/ dead pathogen
- Dead pathogen stimulates production of antibodies
- Antibodies destroy pathogen
- Antibodies are left as memory cells in the lymph nodes
- When a 2nd infection of the same pathogen occurs, the memory cells produce antibodies rapidly
- This causes no symptoms
What is herd immunity?
When the majority of the population is vaccinated, it prevents the spread of the disease
What do antibiotics do?
Destroy bacteria
Name an example of an antibiotic
Penicillin
What are painkillers?
Relieve the symptoms of an illness
What is resistant bacteria?
Bacteria that isn’t destroyed by a specific antibiotic - happens when someone overuses antibiotics or a mutation
Where does digitalis originate from?
Foxgloves
Where does aspirin originate from?
Willow bark
Who discovered penicillin and how was it discovered?
Alexander Fleming from Penicillium mould.
How were drugs made traditionally and now?
Traditionally: from plants and microorganisms
Now: By chemists in the pharmaceutical industry (labs)
What is preclinical testing?
When drugs are tested on cells and tissues, then they are tested on animals (rats) to test for efficacy, toxicity and dosage
What happens after preclinical testing?
They are tested on healthy volunteers to make sure there aren’t harmful side effects , given at very low dose but increased
What happens after the drug is tested on healthy people?
Tested on ill patients to find out the optimum dose
What happens after the drug is tested on ill people?
Some people are given the real drug some are given the placebo so that the doctor can see the difference - placebo effect
What is the placebo effect?
When the patient exppects the treatment to work and so feels better, treatment did nothing
Why do double-blind trials happen?
So doctors aren’t subconsciouly influenced by their knowledge and remain unbiased.
What happend before a drug is published?
Peer reviews to prevent false claims
What are monoclonal antibodies?
Antibodies produced from lots of clones of a single B-lymphocyte cell
How are monoclonal antibodies made?
- Mouse if injected with an antigen
- B-lymphocytes are stimulated and produce antibodies against it
- Antibodies are fused with tumour cells so that there are many clones
- This forms hybridoma cells
- Hybridoma cells produce monoclonal antibodies
- Monoclonal antibodies are collected and purified
How are monoclonal antibodies used in pregnancy tests?
Pregnant women’s urine have a hormone called HCG
How do preganancy tests work?
- Woman pees on stick that has some antibodies
- urine passes through reaction zoone
- HCG hormone binds to the mobile HCG antibody
- HCG hormone binds to the immobilised HCG antibodies in the results zone
- antibodies which dont attach to HCG, binds to antibodies in control zone
- blue dye appears in both control and results zone - positive results
How can monoclonal antibodies kill cancer cells?
Antigens on cancer cells are called tumour markers. MA will bind to these because anti-cancer drugs (could be a toxic drug that stops growth) can be attached. Antibodies given to patient through a drip. Antibodies bind to tumour markers and drug kills cancer cells.
How can MA find specific substances in the blood?
MA are made to bind to the specific molecule. Antibodies are then bound to a fluorescent dye. If molecules are present, antibodies will bind and can be detected using a dye
Side effects of MA
- Fever
- Vomiting
- Low BP
Why do plants need nitrate?
To produce proteins- without it = stunted growth
Why do plants need magnesium ions?
Production of chlorophyll, without it = chlorosis - yellow leaves
Signs of disease on plants
- Discolouration
- Growths
- Stunted growths
- Decay
- Aphids present
- Malformed stems
What do aphids do?
- Virus vectors
- Distubs balance in hormones
- Suck sap on phloem
- Secrete honey dew - mould grows = fungus
- Saliva causes allergy on plants
Physical defences on plants
- Tree bark
- Cellulose
- Waxy cuticle
All stop pathogens from entering
Chemical defences on plants
- Poisons e.g foxgloves
- Antibacterial cheimcals e.g mind plant kills bacteria
Mechanical defences on plants
- Thorns or hairs
- Mimicry
- Droop/curl
How is fungi a pathogen?
- Some are Single-celled
- Others have a body made up of hyphae which grow and penetrate human skin and surface of plants = diseases
- Hyphae can produce spores which can be spread to other plants and animals
Are viruses living organisms?
No, no cells
Why are placebos used?
To act as a control and to compare he effcets of treatment vs no treatment
Why do MAbs help patients?
MA antibody binds to the virus. The MA is complementary to the antigen of the birus. WBC kill the virus
Uses of MAbs
To diagnose cancer, locate blood clots, locate specific molecules
Ways to reduce spread of respiratory disease
- Regular hand washing
- Face Mask
- Isolation
- Dont share cutlery
- Disenfect surfaces
- Cover nose when sneezing
How can MABS and a fluorescent dye be used to see any pathogens on the slide
- Bind dye to MAbs
- MAbs will bind the pathogens and show up under microscope
Why are human lymphocytes more effectuve then mice?
Our body less likely to reject them
What happens when the phloem and xylem are damaged?
Phloem: less transport of sugar to root cells
Xylem = less water, nitrate Mg to plant
What happens if plants absorb less water?
Lower rate of photosynthesis - less cellulose - feweer cell walls made - few amino acids to make new proteins
What sugar does translcoation transport?
Sucrose
Diff of transpiration and translocation
- Translocation: needs energy, phloem, transports sucrose
- Transpiration : no energy needed, xylem, loss of water
Why dont large organisms use diffusion? Why do they have respiratory systems?
Diffusion distance too large
Why do larger organisms have a higher metabolic rate?
- Lose heat quicker so needs a greater rate of respiration (part of metabolism)
- Needs to generate more heat to stay warm
What does microvilli do for villi?
Increase SA
What do the cells of villi have?
Many mitochondria, more active transport, more absorption
What does a good blood supply for alveoli and villi mean?
Maintain conc gradient
What do tears have?
enzymes that
Nose
- internal hairs, physical barrier to infection
- mucus - traps pathogens
Trachea and bronchi
- Cilia waft their hairs and move mucus and pathogens up to throat where it can be swalowed into stomach
- Goblet cells - create mucus to trap pathogens
Stomach
- HCL - kills pathogens
Skin
- tough barrier
- secretes antimicrobial substances
How does fungi defend itself from pathogens?
antibiotic production - kills bacteria
How do plants defend themselves from pathogens?
cell wall waxy cuticle, bark/dead cells = difficult to penetrate + dead cells fall off, taking pathogens with them
production of antibacterial chemicals - kill bacteria
