Infection and response Flashcards
What is a pathogen
A microorganism that causes a disease
What are two examples of viral diseases with symptoms and how it is transmitted
HIV:
Fever, sore throat
STD
Tobacco mosaic:
Changes chloroplast colour to yellow/white
Contact between plants
What are two examples of bacterial diseases with symptoms and how it is transmitted
Gonorrhoea:
Thick green/yellow discharge or pain when urinating
STD
Salmonella:
Diarrhoea, stomach cramps, fever
Uncooked meats
What are two examples of fungal diseases with symptoms and how it is transmitted
Athletes foot:
Stinging, burning
Contact with infected skin
Rose black spot:
Black or purple spots on leaves
Through air or water
What is an example of a protoctist disease with a symptoms and how it is transmitted
Malaria:
Recurrent episodes of fever
Mosquito bites
Required practical : What is the method for culturing bacteria
Disinfect the surface you are woking on
Divide the bottom of the petri dish and label it
Pour sterile agar into the dish
Collect a sample of bacteria with a loop
Open lid slightly and streak the agar
Heat the loop on a blue flame to steralise the loop and repeat
Close the lid and put 4 pieces of tape on the sides so anaerobic respiration won’t take place
Keep at 25°C
What is the first line of defence against pathogens
Skin - physical barrier
Nose - mucus
Trachea and bronchi - cilia
Stomach - stomach acid
What is the second line of defence against pathogens
Phagocytes - engulf and destroy
Lymphocytes - produces antibodies/antitoxins
What is a vaccine
A medicine containing antigens from a dead or weakened pathogen that triggers a low level immune response so that future infection is dealt with more quickly by the immune system
What is the difference between antibiotics, antitoxins and antigens
Antibiotics - a very important group of medicines to kill bacteria
Antitoxins - a substance that neutralises toxins produced by pathogens
Antigens - a protein on the surface of a pathogen that triggers an immune response
What is antibiotic resistance
When antibodies no longer work on bacterial infection
How does antibiotic resistance develop
Bacteria mutates and doesn’t get killed by antibiotic treatment
Reproduces and the next generation inherit the genetic advantage
This keeps happening until antibiotic treatment no longer works
How can you minimise antibiotic treatment
Taking antibiotics when necessary
Specific antibiotics for specific infections
Right dosage
Only for bacterial infections
Take antibiotics for the full amount of time
Why don’t painkillers cure infectious diseases
It only stops the pain you feel
What are the steps for drug development
Testing on cells and tissue:
Tests for toxicity
Animal testing:
Efficacy - does it work and does it give the desired effect
Toxicity - how harmful is it
Dosage - how much and often should it be given
Clinical trials:
Tested on a small amount of healthy people for side effects
Low dosage and gradually increases
Tested on people with the illness - checks for optimal dosage and efficacy
Clinical trials (double blind):
Patients are split into two groups
One group is given the new drug and the other is given a placebo
Results are published in journals
