B3: Infection & Response Flashcards
What is a pathogen?
A micro-organism that causes disease
What are the 4 types of pathogens?
- Bacteria
- Viruses
- Fungi
- Protists
How do viruses reproduce?
Inserting genes into cells which causes them to produce more copies
What are measles and how is it spread?
A virus that causes a rash
Spread by droplets
What is HIV?
An STD/STI that causes AIDS - compromised immune system
How does bacteria make you feel ill?
Releases toxins into your body that damage cells
How is salmonella transmitted and what are it’s effects?
Through undercooked food with bacteria
Food poisoning;
- fever
- abdominal cramps
- vomiting
- diarrhoea
What is gonorrhoea?
An STD
Causes yellow discharge
What do fungi do?
Damage cells
What are protists?
Single-celled organisms
How are protists transmitted?
Through vectors e.g. mosquitoes
What causes malaria?
A protist that infects red blood cells
What is rose black spot?
A fungus that causes leaves to fall off
Can be treated with fungicides
What is tobacco mosaic virus (TMV)?
A virus that results in the discolouration of leaves due to less chlorophyll and therefore stunted growth
What are human defences against pathogens?
- Skin - physical barrier
- Mucus in nose/trachea - traps
- Acid & enzymes - kill
What are plant defences against pathogens?
- Cell wall, waxy cuticle, bark - barriers
- Antibacterial chemicals
- Poison/thorns to deter other organisms
How do lymphocytes remember pathogens and help make you immune?
Once the correct antibody is found, T cells store it in your lymph nodes, ready for next time
What are lymphocytes?
A type of white blood cell that produces antitoxins to neutralise toxins made by pathogens and antibodies that bind to the antigen of a pathogen
This stops viruses from infecting cells and causes them to clump together
Where does aspirin come from?
Willow trees
What are phagocytes?
A type of white blood cell that will ingest pathogens
What is a vaccine?
A dead/inert version of a virus that is injected into your body so that you can gain immunity without becoming ill
What is are disadvantages of antibiotics?
- Difficult to make them target specific bacteria, and not damage our cells or other ‘good’ bacteria
- Whole course must be taken to kill all bacteria, or more resistant bacteria will survive and multiply
Where does penicillin come from?
A mould
What are synthetic drugs trialled for?
- Efficacy
- Toxicity
- Dose
What are the steps in producing a drug?
- Computer testing
- Tested on cell tissue, then animals, then humans
What is a blind trial?
A test group are given a drug, a control group are given a placebo, without being made aware
What is a double blind trial?
Doctors do not know which is which, to eliminate bias
What are monoclonal antibodies?
Produced by clones of a cell that produces a desired antibody?
What are the steps in producing monoclonal antibodies?
- Lymphocytes from mice are combined with tumour cells to make a hybridoma
- Hybridoma multiply, producing lots of the same antibody
What are uses of monoclonal antibodies?
- Combat diseases
- Medical diagnosis
- Pathogen detection
- Identifying molecules; dye is bound to antibodies, which attach to specific molecules
What are disadvantages of monoclonal antibodies?
Side effects are worse than scientists expected
How can pathogens be spread?
- Air
- Water
- Direct contact
