Boitechnology Flashcards
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
