B6 Flashcards
What is an antibody
White blood cell produces it to bind to antigen on pathogen and inactivate or destroy it
What is an antigen
Unique proteins on a cell that white blood cells can recognise as foreign
What are memory cells
White blood cells that recognise an antigen from a previous time so can make the antibody quicker
How does a vaccine work
Inject a dead or inactive pathogen into body, triggers immune response (white blood cells make antibody), if you get the actual pathogen, memory cells will recognise the antigen and produce an antibody quicker
What types of diseases do vaccines work for
Bacteria and viral
What is herd immunity
When a large proportion of the population get vaccinated, it is harder to pass a pathogen around as it gets destroyed quicker in each person
What type of pathogen do antibiotics work against
Bacterial
How do antibiotics work
Kill or damage bacteria cells without causing harm to healthy cells (stop bacteria cells growing), specific bacteria should be treated with relevant antibody
Negatives of antibiotics
- don’t work against viruses
- antibiotic resistant strains of bacteria are evolving
How to prevent antibiotic resistant strains of bacteria
- take antibiotics for whole of the prescribed time period otherwise the strong bacteria that weren’t killed will replicate even if you didn’t have any symptoms
- don’t over use antibiotics
- develop new antibiotics
What did medicines used to come from
Plants
2 examples of drugs from plants
Digitalis is from foxgloves
Aspirin from bark of willow trees
How was penicillin discovered
- Alexander Fleming was growing bacteria for study purposes
- after leaving them over holiday, he realised there were clear rings around some of the mould that had killed the bacteria
- called it penicillin
Future of drugs
Most are now synthesised
However, starting point is still usually a plant or microorganism
4 things a good drug must be
- Effective
- Safe
- Stable
- Successfully taken into and out of body
What does it mean if a drug is effective
Prevent or cure disease or at least make you feel better
What does it mean if a drug is stable
Must be able to use drug under normal conditions and store it for some time
What does it mean if a drug is safe
Can’t be toxic or have unacceptable side effects
What are the 6 stages of drug testing
- Computer model
- Human tissues/ cell
- Animals
- Healthy volunteers
- Ill volunteers
- Placebo
Explain first stage of drug testing
Computer model, check chemical reactions in body
Explain second stage of drug testing
Human tissues/ cells - check damage to cells
Explain third stage of drug testing
Animals - check dosage, effective, side effects and toxicity
Explain fourth stage of drug testing
Healthy volunteers - paid, check max dosage before side effects, doesn’t check effectiveness
Explain fifth stage of drug testing
Ill volunteers - check effectiveness, dosages side effects