INTERMEDIATE 1 BIOLOGY - Hamiltonscience.org

conversesoilBiotechnology

Dec 3, 2012 (4 years and 6 months ago)

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HAMILTON GRAMMAR

SCHOOL


INTERMEDIATE 1
/ ACCESS 3






BIOLOGY








BIOTECHNOLOGICAL IND
USTRIES


STUDENT SUMMARY NOTE
S

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1.

Dairy Industries


Milk


Milk is an important food for most British people.


Milk contains fat, protein, sugar, vitamins and m
inerals.


Milk
can be



pasteurised


skimmed


UHT


powdered.



The milk all comes from the
same source, dairy cows
.



It is
treated differently to
make

all these different types.


Milk is an important part of a balanced diet.


It contains many important nutrie
nts, sugar, fats, proteins,

Vitamins and minerals but this makes a good
place for
ba
cteria to grow.


To kill bacteria all our milk is heat
-
treated in some way.


The heat treatment should

kill all the harmful
bacteria.(Microbes)


The taste of milk is changed by the way it is treated.

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Resazurin dye test


T
o make sure that it is fit to drink before it reaches our
doorsteps or supermarket shelves.


2 main forms of heat treatment:

used to destroy harmful







microbes


Past
eurisation




Pasteurisation is the most widely used heat
-
treatment.




86% of the milk sold in this country is pasteurised.





The milk is first heated to 72

C for at least 15 seconds.





It is then quickly cooled to a temperature below 10

C.




It is then p
ackaged in bottles, cartons or containers and
distributed.





Pasteurised milk will keep for up to five days if it is
stored in a fridge.


Ultra High Temperature (UHT)




UHT milk is heated to a higher temperature than
pasteurised milk.





UHT milk is heated

to between 135

C and 142

C for 2 to
5 seconds.




This processing alters the taste of the milk.




Preserves milk and helps it last longer.

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Milk can also be graded by its fat content so that we can buy


Semi
-
skimmed

skimmed milk


evaporated milk




Wh
ole milk is the most popular in the UK.




When the fat is removed f
ro
m the milk there is also a
reduction in Vitamins such as Vitamin A.


For this reason it is not advisable to give skimmed or semi
-
skimmed milk to young children.

Semi
-
skimmed


half of the fat
removed.


Skimmed milk


almost all the fat
removed.


Evaporated milk


-

half the water
taken
out

-

used like cream

-

way to preserve
milk

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Yoghurt








Makin
g yoghurt is a way of preserving milk
.


The yoghurt which we buy in the shops may be set or stirred.


Stirred yoghurt



inoculated






made in bulk





put into pots.



Set yoghurt


-


inoculated





incubated in the pot in which it is sold.




You can also find different types of natural yoghurt some of
which are known as
bio
-

yoghurt
.


Bio

yoghurt


1.

These natural yoghurts can be used as the “starter”
culture to allow us to make yoghurt in the lab.


2.

The starter cultures contain bact
eria.


3.

When the bacteria grow they make lactic acid from the
pasteurised milk
.


4.

The lactic acid gives the yoghurt its taste and makes the
milk thicker.


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Cheese















There are several steps in the manufacture of cheese:







the milk is pa
steurised to kill most of the bacteria





Rennet is

added to
milk to make cheese
.





The rennet clots the protein in milk to make curds.






Whey is the liquid left when the curds are made.





Bacterial cultures are also added to milk





They convert sugar to a
n acid which helps clot the

protein.





This can also affect the flavour of the milk.



Rennet


Rennet

contains milk clotting enzymes.

T
he enzyme

i
s used in cheese making
and
can come from a
variety of different sources:




rennet from calves




genetically mo
dified fungi grown in fermenters.



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Monitoring waste



When cheese is made the solid curds go on to form the cheese
but the liquid whey is a waste product.


If the whey was put untreated into the rivers it would cause a
build up of bacteria in the rivers.


These bacteria would use up the oxygen in the rivers and there
would be less oxygen available for the fish and all the other
living organisms.

This leads to less living organisms found in the
rivers.


To protect the environment the whey must either be trea
ted
before it is released into the rivers or it must be used for
something else (upgraded).


The whey is treated by using bacteria which feed on the whey
and turn it into carbon
-
dioxide and water. The bacteria are
then removed and the clearer water

is dis
charged into the
river.
The river water is tested to make sure that the oxygen
level is satisfactory.


The whey can be used in industry. Some types of yeast feed
on whey and if they are given the right conditions they change
the sugars in the whey into al
cohol. This type of alcohol is
creamy and is found in products such as Baileys Irish Cream.


Whey can also be used to feed animals.






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2. Yeast Industries













Bread


For thousands of years humans have been using yeast

in making
bread dough.



Yeast is a simple fungus.


Yeast is added to flour to make the dough rise.


Yeast is a living organism and when it respires
( breaths) it
gives out carbon
-
dioxide.
It is this gas from the yeast which
makes the bread rise.


Pure cultures of yeast cells c
an be grown in huge numbers in
large vessels called
fermenters.


The yeast can then be used by the baking industry to make
bread or by the brewing industry to make beer.










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Beer































Making Beer



Factors affecting
al
cohol content




type of yeast



the temperature



fermentation time


All beer must be matured before it can be drunk.


Maturing the

beer improves
-


flavour







r
emoves

solid material








gives it sparkle

Around half the
beer whic
h is
drunk
today is
lager and the other
half is bitter, ale
and stout.

Different be
ers are brewed in different ways and
they have different alcohol contents.

In Britain today
there are over
1200 different
brands of beer.
Each brand is
different and
has its own
flavour.


An alcoholic
drink made
from water,
barley, sugar,
hops and yeast
.


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In beer making yeast converts sugar into al
cohol and carbon
dioxide.
This process is called fermentation
.



The beer is





Cask conditioned beer



Brewery

conditioned beer


























-

Often called Real
Ale


-

Made in casks


-

The yeast is

not
removed


-

Fermentation and
carbon dioxide
production
continues in cask.



-

for sale in kegs,
bottles or cans


-

stored in large
tanks


-

yeas
t is removed


-

carbon dioxide is
added.


-

t
his type of beer
such as lager is
therefore clear
and bright and
has a longer shelf
life than cask
beer


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Fermented milk drinks



In many countri
es it is difficult to keep milk
fresh.


One way of solving
this problem is to ferment the milk slightly
to make it alcoholic.


An enzyme is added to milk to convert some sugar to lactic
acid.


Yeast is also added and converts some sugar to alcohol and
carbon dioxide.


The product is a fermented milk drink.


In so
me areas of the world a drink called
kefir
is made in this
way. Drinking kefir is like drinking a fizzy, slightly alcoholic,
yoghurt drink.


Immobilisation





1.

C
an be used to make kefir.


2.

A
fter the reaction the beads can be washed and reused.
This sa
ves money because the enzymes can be very
expensive.


3.

T
he bead can be easily separated from the product.

4.

This would not be possible if the enzyme and the yeast
were free in the yoghurt drink rather than trapped in a
bead.

U
sed to trap an enzyme and some ye
ast into a jelly bead.

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Food flavourings and colourings



In addition to using yeast for making bread and alcoholic
drinks, yeast can be used for flavouring food.


Y
east flavourings
are added

to
soups
,
crisps and snacks.




Wild salmon and trout have pink flesh from the pink coloured
prawns and shrimps which t
hey eat.




Farmed salmon and trout would be a dull grey colour if they
were not fed a red dye in their diet just before they are killed.


The dye does not affect the way that the fish tastes and it is
only added because people do not want to eat grey s
almon or
trout.


It is now possible to give the salmon a red colour by feeding
them red yeast. The fish then take on a pink colour in their
flesh.













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Monitoring waste



It is very important that the waste from yeast industries is
not dumped in

rivers.


The yeast would provide food for bacteria and the rivers would
become polluted.


Yeast industries treat all their waste and much of it is
upgraded and used for animal feed. This means that the water
leaving the factory can be put into the ri
ver without causing
pollution.


Before the water is put into the river it is tested to make sure
that it will not cause pollution.





















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3.

Detergent Industries


Biological washing powders


The word
detergent

means



Some washing powders are
known as







Biological washing powders contain


Enzymes are produced in
large quantities by bacteria cultured
in industrial
fermenters and are added to the washing powder
because they improve the way in which it cleans.


B
iological washing powder















1% enzymes

water softeners

bleach

chemicals


biological washing powders.

enzymes.


“something which cleans”.

Soaps, washing up liquid
and washing powder


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The use of enzymes in washing powders





1.

E
nzymes in washing powders digest the stains in the

same way that enzymes in your gut help to digest

your food.



2.

Different enzymes are added to digest different

stains.




F
at digesting enzy
mes are a
dded to digest fatty stains

starch digesting enzymes are added to digest starchy

stains.



3.

The enzymes themselves make up a very small part of the
powder but they make up a large part of the cleaning
power of the powder.



4.

When powders con
taining enzymes first came into the

shops some people found that the
y

had an allergic

reaction to the powder.



5.

Once this was discovered the detergent industry

introduced new powders where the enzymes had been

coated
to prevent allergic reactions,

which can cause skin

rashes and eczema.

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6.

Enzymes in washing powders are now all coated with a

waxy substance and they form granules.



7.

The addition of enzymes to washing powders means

that

we can all have cleaner clothes as the stains are

diges
ted.



8.

Another major benefit is that these biological powders

work best at low temperatures and this saves energy.


Fuel consumption is reduced which can help in reducing

pollution caused by the burning of fossil fuels in power

stations.


9.

In the p
ast before enzymes were added to washing

powders the temperature of the water had to be much

higher before the clothes would become clean.



10.

The enzymes in the biological washing powders work

best

at temperatures of between 40

C and about

55

C.



11.

The enzymes are destroyed at temperatures above

60

C.



12.

The lower temperatures used in washing with biological
powders are also kinder on clothes as high

temperatures
can damage delicate fabrics.



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Monitoring waste







production,

packagin
g

and
transp
orting of detergents




greatest
use of energy is in the
home.








Heating the water for the washing machine, the wash
cycle
, tumble drying and ironi
ng all

use up energy.


This means that it costs the consumer a lot of money and h
as a
great impact on the environment.


Saving energy


1.

Washing clothe
s at low temperatures.

2.

Reduces fuel consumption.

3.

Contributes to reducing pollution caused by the
burning of fossil fuels in power stations.

4.


Less fuel will be used and this is good news fo
r the
consumer and for the environment.



Detergents in waste water can be toxic to wildlife


Detergents all end up in the environment when they are flushed
away as waste water.


Detergents contain other chemicals which can increase the
growth of algae in
lakes and rivers.


In the home

Energy is used in

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When algae die this can have the same effect as whey released
into rivers.


The manufacturers test their products to see that they would
not harm the fish or the other living organisms found in our
rivers.

The detergent industries

check

their own waste.


Ways to reduce

environmental impact




reduce the chemicals in detergents



sewage works removing the chemicals before releasing
the water into the environment.

















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4.

Pharmaceutical Industries



























1.

Around the time of the Second World War two other
British scientists managed to produce penicillin on an
industrial scale.


2.

Antibiotics then became known as the “wonder drug”
-

they cured so many people

who would have died.





Produced c
ommercially
in automated industrial
fermenters.


There are
many
different
types of
antibiotic.


Destroy and prevent
the further growth of
bacteria.

Produced
naturally by
fungi from soil


Antibiotics

They were
discovered
by Alexander
Fleming.


Penicillin
-

most common
antibiotic


Only ac
t on
bacteria and not
on viruses.


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Making Antibiotics



1
.

To meet the massive demand for antibiotics in the
modern world huge fermenters holding over 200,000
litres have been designed.


2.

Careful attention has been paid to produce the best
growth conditions and the vessels are automated and
controlled by com
puters.


6.

Sterile conditions must be maintained in the fermenter.


7.

Growth conditions are altered automatically by the
computers for example if the temperature in the
fermenter becomes too warm the computer detects the
change and cools down the mixture
.


8.

Finally the antibiotic has to be purified
-

this involves
filtering and solvent extraction.



Genetic modification
;








-

is a new technology which alters the genes
found in living things.


-

can be used to produce new antibiotics which will be more
effective for fighting disease.


-

Computer
-
control technology is used to monitor and
adjust growing conditions, e.g. temperature


-

Computer
-

control can help purification of the antibiotic.


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Advantages

of antibiotics


1.

Different antibiotics are effective
against different
infections.


2.

Penicillin is used to treat a wide range of infections
including respiratory infections.



Disadvantages

of antibiotics


1.

When antibiotics first appeared they were considered to
be the wonder drugs but after some time
it was found
that some infections became resistant to the antibiotic.


2.

This means that the drug no longer kills the bacteria
which is causing the infection.


3.

This has happened because of over
-
use of penicillin and it
is a very worrying trend.


4.

Peo
ple are now also concerned about the over
-
use of

antibiotics in Agriculture and veterinary practice.


5.



The same drugs are used in animals as in humans and the

concern is that over
-
use of antibiotics in animals might

lead to more resistant strai
ns of bacteria.





There is continual pressure to try to produce new antibiotics
which bacteria are not resistant to.


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Anti
-
fungals



Some infections are caused by microbes known as fungi.



Some common fungal infections are
















Drugs known

as anti
-
fungals can be used to treat these
infections.


The anti
-
fungal treatment slows down or stops the growth of
the infection.










athletes foot

thrush