22.4 Microorganisms And Biotechnology Flashcards
What is biotechnology?
What is bioremediation?
The industrial use of living organisms to produce food (e.g. cheese, yoghurt, wine), drugs, and other products.
Bioremediation is the use of biological systems to remove soil and water pollution
- the most commonly used organisms in biotechnology is fungi, particularly yeasts, and bacteria
Why are bacteria and fungi (microorganisms) the organisms most commonly used in biotechnology processes?
- their ideal growth conditions can be easily created— microorganisms will generally grow successfully as long as they have the right nutrients, temperature, pH, moisture levels and some need oxygen
- due to their short life cycle, they grow rapidly under the right conditions, so products can be made quickly
- they can grow on a range of inexpensive materials — this makes them economical to use
- genetic engineering allows us to artificially manipulate microorganisms to carry out synthesis reactions that they would not do normally
- they can be grown at any time of the year
Describe and explain the use of enzymes in biotechnology
Enzymes used in industry can be contained within the cells of microorganisms - intracellular enzymes
Enzymes are also used that aren’t contained within cells - isolated enzymes
Some are excreted naturally by the microorganisms - extracellular enzymes, but other enzymes need to be extracted (which can be expensive)
List the foods that microorganisms can be used to make via biotechnology
- baking bread
- brewing beer
- cheese making
- yoghurt making
Describe and explain how microorganisms are involved in brewing
To make beer, yeast is added to a type of grain (e.g barley)
- yeast respires anaerobically using the glucose from the grain and produces ethanol (alcohol) and CO2
This is an example of fermentation
Describe and explain how microorganisms are involved in baking
Yeast makes bread rise
The CO2 produced by fermentation (anaerobic respiration) of sugars in the dough makes sure it doesn’t stay flat
Yeast cells are killed during cooking (e.g. in the oven)
Describe and explain how microorganisms are involved in cheese making
Cheese production relies on a substance called rennet
Rennet contains the enzyme chymosin, which clots the milk. Traditionally we used to get chymosin by extracting rennet from the lining of the calves’ stomach
But now chymosin can be obtained from yeast cells that have been genetically modified to produce the enzyme
Cheese making also involves lactic acid bacteria
These bacteria convert lactose in the milk into lactic acid, which turns it sour and contributes to solidifying
The production of blue cheese also involves the the addition of fungi
Describe and explain how microorganisms are involved in yoghurt making
Involves lactic acid bacteria to clot the milk and cause it to thicken
How can microorganism act as a source of protein?
Some microorganisms can be grown as a source of protein (called single-cell protein), which acts as a valuable food source to humans and animals
E.g. fungus is used to make single cell protein (mycoprotein) used to make Quorn
Advantages of using microorganisms to produce human food
- microorganisms used to make single-cell protein can be grown using different organic substrates, including waste materials such as molasses. So its good to get rid of waste products
- microorganisms can be grown quickly, easily and cheaply
They have simple growth requirements - microorganisms can be genetically modified to produce required protein
- production of microorganisms can happen at any time
- microorganisms have high protein content with little fat (healthier alternative to animal protein?)
Disadvantages os using microorganisms in food production
-need sterile conditions, which adds to costs, in order to avoid contamination
- people have concerns over GM food
- people dislike the thought of eating food that has been growing on waste products
-single cell protein doesnt have same texture or flavour as real meat
