Plant uses, bacteria & drug testing Flashcards
What does it mean if a plant has anti microbial properties?
It means that it is effective in fighting off microbes. Plants are vulnerable to attack by pathogens.
How do plants protect themselves?
They have evolved ways of fighting pathogens, and having antimicrobial properties is one of them. Also, they can store compounds which are toxic to microbes but are not harmful to them.
How do humans use plants’ anti microbial properties?
Many of the plants which have been found to have antimicrobial properties were already in use by local communities for medicines. Experimentation has confirmed the properties which people thought they had.
Where can you make plant fibres and what do they contain?
Plant fibres can be made from seeds, bark and leaves, and tend to contain cellulose, hemicellulose and lignin in varying proportions
What is the common use for plant fibres?
Plant fibres are most known for their use in the textile industry. Cotton is a plant fibre made from seeds. It is used to make lots of different textile products. Linen is made from the stems of the flax plant. Linen is used to make bed sheets and tablecloths etc.
How is starch used in industry?
Starch can be broken down and fermented to produce ethanol, which can then go on to be used in making beer, or biofuels. Processed foods often contain sugars which were taken from starch.
How do plants help sustainability?
Plant-based products could help contribute to sustainability. For example, plastics that are currently oil-based could be replaced by plant-based plastics. Plants are a renewable resource, so if managed correctly they offer a sustainable alternative to fossil fuels.
What conditions maximise the growth of bacteria?
- Temperature
- pH
- Food & water availability
What is the optimum temperature for bacteria to grow?
Most bacteria do better in warm temperatures, between 25 and 40 degrees
What are mesophiles?
Organisms which experience optimum growth at moderate temperatures
What is the optimum pH for bacteria to grow?
Most bacteria have an optimum pH that is neutral, so around 7
What is the optimum food availability for bacteria to grow?
Bacteria need nutrients to survive, they can be taken from various sources, including fats, sugars and proteins
What is the optimum water availability for bacteria to grow?
Moist environments tend to be perfect for bacteria to grow. Water is needed to take in nutrients, remove waste products and perform metabolic reactions.
How can scientists grow bacteria?
In a lab, they can grow microorganisms on an agar plate, which acts as a growth medium by providing nutrients
How can knowing the optimum conditions for bacteria help?
It can help to prevent their growth, particularly applicable in the safe storage of food. For example, adding acidic preservatives or freezing food.
How were drugs found in the past?
Either discovered by chance, or found in a remedy that was already thought to have useful properties
Who is William Withering?
A scientist working in the 1700s, who ran one of the earliest examples of a drug trial
What drug did William Withering discover?
He observed that a person recovered well from edema after being given a remedy that contained foxglove. He determined that digitalis was the active ingredient.
How did Withering find out the best dose?
He made up different ‘digitalis soups’, which had different concentrations of digitalis in them. He tested the doses on patients, using trial and error to work out the correct one.
What does trialling a drug do?
It is a good way to test whether they are effective on the targeted group, and to make sure that they are safe to use
What is a double blind trial?
A trial where neither the people in the trial nor the researcher running the trial know which treatment has been given to which people
What happens during a double blind trial?
Some people in the trial will have been given the new treatment that is being tested, and others will have been given a placebo
What are the benefits of using a double blind trial?
It ensures that there is no bias by the patients or researchers. The treatment group is completely randomised by a computer.
What is a placebo?
It is a drug which does not have any effect on the patient because they do not work
