Chemical defences are adapted to provide chemical defences to repel & kill animals that feed on them.
What are natural antibacterials used for?
flavourings in foods or tea, toothpaste, garlic used in antibiotics
What are some medicines from plants?
foxgloves & 'dropsy'
Garlic extracts have been found to destroy bacteria which cause intestinal infections – this can be more effective than the use of antibiotics because of resistant bacteria.
What is allicin?
Produced when a plant is cut. Some parts of the plant tend to have greater antibacterial properties than the rest.
WHO estimates 75%-80% of the world’s population uses extracts from plants as medicines – aspirin derived from extract of willowbark), morphine & codeine both derived from opium poppies.
What is 'Dropsy'?
Oedema - it can lead to death if the fluid fills up in the lungs.
What is 'dropsy' normally due to?
It is normally due to an irregular heartbeat & increased blood pressure.
What is normally used to treat 'dropsy'?
Foxglove
What was the first evidence of 'drug testing'?
William Withering who investigated the properties of foxglove and released his work in 1775.
What are the 5 stages of drug trialling?
Pre-clinical testing, 3 phases of clinical trials, licensing trials
What is a placebo?
Contains an inactive compound, appearance is identical to the active form of the drug
What is a double-blind randomised trial?
When neither the patient or the researcher know who is receiving the drug/placebo, gold standard
William Withering VS the current system of drug trialling:
What are some similarities in Williams to current drug trialling?
both identify the medicinal substance, both test on small groups initially, both go on to test on larger groups of patients
What are some differences in Williams to current drug trialling?
Animal trials used in modern method whereas Withering did not, drug tested on small group of healthy people first whereas Withering did not, modern trials use placebos, modern trials use double blind randomised trials whereas Withering did not
How are seeds adapted to ensure the survival of a plant?
protect the embryo, aid dispersal, provide nutrition for the new plant
Main Parts of a Seed:
How does seed germination work?
1.the seed takes in water through a small pore in the seed coat
2. absorbing water triggers metabolic changes in the seed
3. enzymes are produced which convert storage molecules into usable forms - providing a source of energy and raw materials for growth
Maltase and amylase break starch into glucose which is transported to radicle and plumule.
Proteases break down proteins into amino acids and lipases break down stored lipids into glycerol and amino acids
What is starch?
A long-chain polymer made of alpha-glucose monomers (carbohydrate)
Why is starch easy to extract from plants?
It's a granule and doesn't dissolve in water but can be washed out