biotechnology need to know

8/8/2019 Biotechnology NEED to Know

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Biotechnology

What you NEED to know

Dairy Industries:

Milk is a food containing sugar, fat, protein, vitamins and minerals

Milk contains bacteria

The level of bacteria in the milk is used as a test of freshness

Resazurin dye is used to show the level of bacteria in the milk and

therefore its quality.

Colour of Dye Milk Quality

Purple GoodMauve Satisfactory

Pink Poor

Clear Unfit to drink

Heat treatment destroys bacteria

Pasteurisation destroys disease causing organisms

UHT treatment preserves milk and prolongs shelf life

Milk Treatments Result

Remove 50% water Evaporated milk

Remove all fat Skimmed milk

Remove 50% fat Semi-skimmed milk

Heat to 72oC for 15 seconds Pasteurised milk

Heat to 142oC for 5 seconds UHT milk

Treatments change the taste of the milk

Yoghurt:

Adding bacteria to pasteurised milk makes yoghurt

Sugar in the milk is changed to lactic acid. This thickens the milk

and gives yoghurt its flavour

Yoghurt is a way of preserving milk

Method Heat to 43oC

Add starter culture of bacteria

Incubate at 43o

C for 7 hoursStore in fridge


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Cheese:

Method Add special bacteria to pasteurised milk

Bacteria convert sugar to lactic acid and affect flavour

Enzymes (rennet) are added to clot the milk Rennet is an enzyme used to clot protein in milk

The clotted protein is solid and called curds

The liquid left over is called Whey

Rennet comes from Calves

Genetically engineered yeast

Fungus

Environmental Impact of Dairy Industry:

Whey is a food source for bacteria

If put into rivers Bacteria multiply

Oxygen levels fall

Other animals die due to lack of oxygen

Whey can be upgraded changed into something useful

Yeast can be fed on whey in a fermenter while they are growing

and making alcohol (e.g. Baileys Irish Cream)

Food for animals

Yeast Industries:

Bread:

Yeast is a single celled fungus

Yeast can be grown in huge numbers in fermenters

In bread making yeast produces carbon dioxide to make dough rise

Beer:

Beer is made form water, barley, sugar, hops and yeast

The type of yeast, the temperature and the fermentation time

affect the alcohol content of the beer

Fermentation is the process of yeast converting sugar to alcohol

and carbon dioxide

Cask conditioned beer is real ale yeast is not removed and carbon

dioxide is continually produced


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Brewery conditioned beer has had the yeast removed and carbon

dioxide is added

Kefir:

To preserve milk it can be fermented

Enzymes are added to convert milk sugar to lactic acid

Yeast is added to convert milk sugar to alcohol and carbon dioxide

Kefir is a fermented milk drink

Immobilising the yeast and enzymes means that they can be used

over and over again and are easily separated from the product

Flavourings:

Yeast is added to crisps, oxo cubes and marmite

Red yeast is fed to farmed salmon to give them pink coloured flesh

Environmental Impact of Yeast Industry:

Yeast based waste is a food for bacteria

If out into rivers Bacteria multiply

Oxygen levels fall

Other animals die due to lack of oxygen Yeast can be upgraded

Food for animals e.g. cattle cake

Fed on waste whey which is converted to alcohol (Baileys Irish

Cream)

Detergents:

Biological detergent contains enzymes

The enzymes are made by bacteria in large fermenters

To prevent allergic reactions, the enzymes are inside a harmless

coating

The enzymes digest stains at a lower temperature

Biological washing powders save energy and reduce damage to

fabrics

Temperatures above 60oC destroy the enzymes

Environmental Impact of Detergent Industry:


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Washing at lower temperatures reduces fuel consumptions

Pollution could be reduced because less fossil fuels are burned in

power stations

Detergents contain chemicals which increase algae growth in rivers

When the algae die they are food for bacteriaBacteria multiply

Oxygen levels fall

Other animals die

Environmental impact can be reduced by

Reducing the chemicals in detergents

Removing the chemicals at the sewage works before release

Pharmaceutical Industries:

Antibiotics:

Alexander Flemming discovered antibiotics

Fungi naturally make antibiotics

Antibiotics destroy and prevent further growth of bacteria

Antibiotics only act on bacteria not viruses

Different antibiotics are effective against different bacteria

On an agar plate the wider the clear zone, the more effective the

antibiotic against the bacteria Antifungals are chemicals which limit the growth of a fungus

Fungal infections such as athletes foot and thrush are treated

using antifungals

Antibiotics can be made using genetically modified micro-organisms

(their genes have been changed so that the micro-organism makes

different chemicals than it normally would)

Antibiotics are made in large fermenters

Fermenters are computer controlled to monitor conditions e.g.

temperature

Antibiotics are easily removed and purified from the fermenter

Environmental Impact of Pharmaceutical Industry:

Overuse of antibiotics can result in bacteria being resistant to

them they stop destroying the bacteria

New antibiotics are continuously being developed


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biotechnology need to know

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