Pathogens and Antibiotics Flashcards
What are pathogens?
Micro-organisms
Give some examples of micro-organisms.
Bacteria and Viruses.
What do pathogens cause?
Disease
What is the difference between bacteria and viruses?
Bacteria release toxins whereas viruses damage our cells.
How can white blood cells help us get rid of infectious disease?
They ingest and destroy pathogens by producing antibodies that destroy the infectious micro-organisms.
What types of cells are bacteria?
Living cells that can multiply rapidly.
Give some examples of diseases caused by bacteria.
Food poisoning
Cholera
Typhoid
Whooping cough
How do viruses reproduce?
Inside host cells, damaging them.
What happens once the virus has made thousands of copies of itself?
They fill the host cells and burst it open.
How do viruses spread throughout the body?
The bloodstream and the airways.
Give some examples of diseases caused by viruses.
Flu Colds Measles Mumps Rubella Chicken Pox AIDs
What are antibodies and antitoxins?
Specialised proteins.
What are antigens?
Chemicals in a pathogen that are foreign to the body.
What are lymphocytes?
Certain white blood cells that can produce specific antibodies to kill a particular pathogen.
How do antibodies neutralise pathogens?
They bind to pathogens and damage and destroy them.
They coat pathogens and clump them together so that they are easily ingested by white blood cells called phagocytes.
What are phagocytes?
White blood cells that engulf clumps of pathogens.
What is vaccination?
It involves putting a small amount of an inactive form of a pathogen, or dead pathogen, into the body.
What do vaccinations do?
Produce enough white blood cells to protect itself against a pathogen.
What are antibiotics effective against?
Bacteria, but not viruses.
What do vaccinations contain?
Live pathogens treated to make them harmless.
Harmless fragments of the pathogen.
Dead pathogens.
How do we prevent the risk of infection?
Maintain personal hygiene and keep hospitals clean.
Who realised the importance of cleanliness in hospitals?
Ignaz Semmelweiss
What do painkillers do?
Relieve the symptoms of an infectious disease but do not kill the pathogen involved.
What are some examples of painkillers and what they do.
Paracetamol, morphine and aspirin block nerve impulses from the nervous part of the body, or block nerve impulses travelling to the part of the brain responsible for perceiving pain.
What are antibiotics?
Substances that kill bacteria or stop their growth.
Why do antibiotics not work against viruses?
Because they live and reproduce inside cells. Drugs that kill viruses can kill the body’s tissues.
What was the first antibiotic, who discovered it and when?
Alexander Fleming discovered Penicillin in 1928.
What happens because of natural selection?
Bacterial strains can develop a resistance to the antibiotics. This is when in large groups of bacteria, some bacteria are not affected by the antibiotic. These cells survive and reproduce, producing even more bacteria that are not affected by the antibiotic.
What does MRSA stand for?
Methicillin-resistant Staphylococcus Aureus
What is MRSA?
A dangerous strain of bacterium that is resistant to most antibiotics.
How can we avoid other strains of resistant bacteria?
Avoid the unnecessary use of antibiotics.
Complete the full course of antibiotics.
How do resistances develop?
Step 1 - Antibiotics kill individual pathogens of the non-resistant strain.
Step 2 - Resistant individual pathogens survive and reproduce.
Step 3 - The population of the resistant pathogens increases.
How can we produce the development of resistant strains of bacteria?
Avoid using antibiotics for infections that are not serious, such as mild throat infections.
Who discovered how to grow bacteria in a petri dish and when?
Robert Koch in 1878.
Which diseases did Robert Koch discover?
TB and Cholera.
How do we grow bacteria in a sterile environment?
Petri dishes, nutrient agar jelly and other culture media must be sterilised.
Inoculating loops used to transfer micro-organisms must be sterilised by passing it through an inoculating loop.
The lid of the Petri dish is sealed with sticky tape to stop micro-organisms from the air getting in and contaminating the culture.
Why is it dangerous to grow bacteria at body temperature?
Because it might allow the growth of pathogens harmful to health.
