Boitechnology Flashcards
(32 cards)
What is biotechnology
Using living organisms to produce useful materials or to provide people with services
What is a fermenter
A container full of culture medium which microorganisms can grow and reproduce in
It must have the right conditions for microorganisms to grow and produce their product on a large scale
What is the first stage of fermentation
Food is provided in the liquid culture medium
Microorganisms need carbohydrates nitrates vitamins and minerals
What is the second stage of fermentation
Air is supplied to the microorganisms if they respire aerobically
What is the third stage of fermentation
The micro organisms must be kept at the right temperatures
Most microorganisms give off heat by respiration so a water jacket is used to cool the fermentor
What are the final stages of fermentation
Instruments are used to monitor the ph
Sterile conditions are needed
A stirrer keeps the culture well mixed so all of the microorganisms get oxygen and nutrients
How do you measure the rate of co2 production with yeast
Boil water in a test tube to remove dissolved oxygen
When cooled dissolve a small amount of yeast and sugar in the water
Add a layer of paraffin to keep out the oxygen
Attach a bung with a tube leading to lime water
The lime water let’s you test if co2 is being released
You can count the bubbles to test the amount of co2 given off
What is mycoprotein
It is used to make meat substitutes for vegetarian meals
Fusarium is grown in fermenters using glucose syrup as food
The fungus respites aerobically
It contains more protein and fibre and less fat than real meat
How is bacteria used to ferment milk to make yoghurt
Yoghurt is fermented milk
The equipment is sterilised
The milk is pasteurised
A starter culture of lactobacillus bacteria is added and the mixture is incubated
The bacteria ferment the lactose sugar in the milk to form lactic acid
This causes the milk to solidify and clot
Flavours and sometimes colours are added and the yoghurt is packaged
How to investigate the effect of different factors on yoghurt making
Add 25cm3 of milk to test tubes and pasteurise
Add 1cm3 of yoghurt to the tubes
Incubate for 5 hours at 5 different temperatures
Measure the ph
As yoghurt is made the Ph decreases from 7 to 4 as lactic acid is made
40c is the best temp so the ph should be around 4
What are the advantages of using microorganisms for food production
They can grow very quickly
They’re easy to look after
The food can be grown in any climate
They can uses waste products from agriculture and industry as their food
They are usually cheaper than other methods
How are enzymes used in washing powder
Biological washing powders contain the same chemicals as non bio ones but also contain a mixture of enzymes
They’re more effective at low temperatures
They work best at ph7 so hard water can damage the enzyme
How is Chymosin used
Cheese is made using rennet
Rennet comes from the lining of a calfs stomach it contains chymosin
It clots milk
Vegetarian cheese is made from man made chymosin
The chymosin genes were isolated then out into Yeats cells and grown to product chymosin
How is invertase used
It is used to make sweets and other foods
It converts sucrose into glucose and fructose which taste sweeter
So less sugar is needed for the same sweetness
So it is cheaper for manufacturers and produces lower calorie sweet foods
It is naturally produced by yeast
Why do we immobilise enzymes
When enzymes are in reactions they can dissolve in the mixture which makes them hard to remove
Immobilised enzymes don’t need to be separated from the mixture at the end
Immobilised enzymes are attached to insoluble material or are in alginate beads and the insoluble material with immobilised enzyme can be washed and reused
How are immobilised enzymes used to make lactose-free milk
Some people lack the enzyme lactase so can’t break down lactose
Mix sodium alginate and lactase together in a syringe
Add the mixture a drop at a time to calcium chloride
Beads will form
Add the beads to a syringe with a nylon gauze
Add the milk to the syringe
Collect the treated milk in a beaker and test the glucose content
How is pectinase used
It breaks down pectin causing cells in fruits to release their juices
Cut the apple up into two beakers
Add pectinase solution to one and water to the other and stir
Incubate the beakers at 40c for 15 mins
Filter and record the volume from each beaker
The beaker with pectinase will have much more juice
How is bacteria engineered to produce human insulin
A plasmid is removed from the bacteria
The insulin gene is cut out of the human chromosome using restriction enzymes
The plasmid is cut open using the same restriction enzyme
The two genes are put together
Ligase is added to join the two sticky ends together and produce recombinant DNA
It is inserted into the bacterium
The modified bacterium is grown in a fermenter
How is agrobacterium tumefsciens used to genetically modify plants
It is a pathogen that invades plant cells and inserts its genes into the plants DNA
If other genes are added by Genetic engineering then they also invade the cell
It acts as a vector
This is how you make a plant resistant to herbicides
The plants are grown in herbicide the ones that grow must contain the gene so they are reproduced
What do restriction enzymes do
Recognise specific sequences of DNA and cute them out leaving unpaired bases at the ends called sticky ends
How are crops genetically modified to be resistant to enzymes
Bt toxin kills of the insect larvae that are harmful to crops
The gene for bt toxin is inserted into the crops making them resistant to enzymes
The toxin is specific to insect pests, harmless to humans, animals and other insects
The insects that are constantly exposed to the toxin have a danger of developing resistance
How can biotechnology be used to get more food for developing countries
Crops can be genetically engineered to be resistant to pests improving yield
They can be engineered to grow in drought and extreme weather conditions
Extra nutrients can be added such as golden rice has beta carotene which can be converted to vitamin a
Why are some people against biotechnology
Many people say that there is enough food but people can’t afford it so we need to tackle poverty first
Some countries could become dependent on companies who sell gm goods
Gm crops won’t survive poor soil
Why are genetically engineered tomatoes good
Snapdragon flowers contain flavonoids which are thought to have anti cancer properties
Scientists have genetically modified tomatoes so they are purple and contain flavonoids
They are an easy way to get the flavonoids to people in developing countries
