6.3 Discovering drugs Flashcards
Described how Alexander Fleming discovered penicillin?
3 marks
- He noticed a clear ring in jelly around some spots of mould growing on bacterial culture plates.
He realised that a chemical in the mould must have killed the bacteria in the culture, leaving the jelly clear.
Suggest reasons for using synthetic forms of drugs rather than using plant extracts directly?
- Plant extracts may be impure, or there may only be tiny amounts in a plant, meaning huge amounts of plant material would be needed to extract the drug.
Synthetic drugs can be made industrially in large amounts and chemists can change the molecules to change the properties of the medicine.
Chemists make effective drugs with fewer side effects than natural products.
What are the ADVANTAGES of looking for new antiobiotic compounds in living organisms based on the example of the noni fruit?
- anecdotal evidence of medicinal properties saves trying many different plants,
- long and widespread usage suggests few side effects;
What are the DISADVANTAGES of looking for new antiobiotic compounds in living organisms based on the example of the noni fruit?
disadvantages:
• may be difficult to source the living material,
• concentrations may be very low,
• may be difficult to isolate the chemical that has caused the antibiotic effect.
What are Ernest Chain and Howard Florey famous for?
First people to Extract penicillin
Who discovered Penicillin?
Alexander Fleming
What drug is extracted from foxgloves and what is it used for?
Digitalis
used to strengthen heartbeats
What drug is found in willow trees?
asprin
How are most new drugs made now?
- synthesised by research chemists working in pharmaceutical industry using chemical banks and computer models. (starting point may still be a chemical extract from a plant or microorganism )
