Biotechnology
1- On what does the raising of dough
and the manufacture of beer and
wine depend on?
2- Describe the processes of aerobic
respiration and anaerobic respiration
in yeast
- in words
- as equations
(C)- Compare aerobic respiration to
anaerobic respiration
Oxygen requirement
Waste products
Efficient at releasing energy from
glucose
Some energy released as heat
3- What is the other word for
anaerobic respiration which produces
alcohol?
3- Describe:
- characteristics of yeast
- uses of yeast for biotechnology
4- (C) Describe how commercial
brewers provide the best conditions
for yeast (3).
5- (C) Explain what is meant by
“batch processing”.
6- (C) Explain the need for malting of
barley before use by the brewing
industry
Unit 1- Living factories
On the activities of yeast.
- in words:
Aerobic respiration: release of energy from glucose (i.e.
food) using oxygen and producing carbon dioxide and water
as waste products – Takes place in all cells when oxygen is
available.
Anaerobic respiration: release of energy from glucose
without oxygen – Produces carbon dioxide and ethanol as
waste products. Not as efficient as aerobic respiration (i.e.
less energy)
Aerobic respiration:
glucose + oxygen → carbon dioxide + water + energy
Anaerobic respiration:
glucose → carbon dioxide + ethanol + energy
Aerobic respiration
Yes, always
carbon dioxide + water
Yes
(most of glucose’s energy
released)
Yes
Alcoholic fermentation
Anaerobic respiration
No, never
carbon dioxide + ethanol
No
(energy locked in ethanol
not available to cell)
Yes, but less
- Single-celled fungus which can use sugar as food and
reproduce by budding.
- making bread (i.e. raising dough), making beer, wine and
other alcoholic drinks.
- food = sugars ( = produced by germinating seeds such as
barley or by sugar rich fruits e.g. grapes)
- correct temperature= need cooling to compensate for
heat released during respiration.
- sterile conditions= contamination by other microorganisms would spoil process.
(wine heated up to kill micro-organisms and cooled down
before yeast is added)
All raw materials (some yeast + nutrients) placed in vessel
(fermenter). Optimum conditions are maintained for yeast
growth (i.e. temperature, pH). Once nutrients are used up
and yeast stops reproducing, liquid (containing alcohol)
separated from solid waste. Fermenter cleaned and
sterilised: ready for new batch.
During malting, enzymes in barley convert starch to
maltose, necessary because yeast is unable to use starch
for food because it is unsoluble.
7- (G) Explain on what the
manufacture of cheese and yoghurt
depends on.
8- (G)State what type of process is
involved in the souring of milk
9- (C) Explain the souring of milk in
terms of bacterial fermentation of
lactose
10- (G) Describe the precautions that
must be taken during laboratory work
with micro-organisms + explain the
importance of such precautions in any
biotechnology work
11- (C) Explain the precautions taken
during manufacturing processes with
reference to resistant fungal and
bacterial spores
12- (C) Explain the importance of the
above
Biotechnology
Use of micro-organisms for the
1- (G)Describe some examples of the
damage done to the environment by
disposal of untreated sewage.
2- (G) Give some example of diseases
which may be spread by untreated
sewage.
3-( G) What is the name of microorganisms used to breakdown
unwanted materials?
4-(G) State the effect of sewage
treatment
5- (C) Explain why complete
breakdown of sewage is only possible
in aerobic conditions (i.e. with
presence of oxygen)
The activity of bacteria
It is a fermentation process (i.e. anaerobic respiration)
During the souring of milk, a type of fermentation turns
the sugar lactose into lactic acid → sharp taste +
coagulation of milk proteins.
Precautions to avoid
1/ contamination of samples by other micro-organisms
2/ contamination of lab tools, clothes etc… from samples
worked with
→Washing hands before work
→ Bench cleaned with disinfectant before and after work
→Wearing a lab coat
→Autoclave all equipment before and after use
→ Work beside Bunsen, flaming loops and necks of culture
bottles.
Precaution to avoid growth of dangerous pathogens
→ Incubate cultures below body temperature
Some pathogenic micro-organisms (i.e. disease causing) can
produce spores which are resistant to most antiseptic
chemicals.
→ equipment needs to be often steam- cleaned to kill
spores
If industrial batch is contaminated:
→ contaminant organism may be pathogenic
→ profit loss for company
Unit 2: Problems and profit with waste
treatment of sewage
- detergents kill wildlife
- bacteria feed on sewage → use up oxygen in water
→ kills species which require high levels of oxygen
- cholera
- typhoid
- dysentry
Decomposers
The breakdown of sewage by decomposers to products
harmless to the environment
Anaerobic respiration: does not release all the energy
contained in food → leaves some sewage substances
untreated.
Aerobic Respiration:
- complete breakdown of food and therefore sewage
- faster
- produce harmless waste products
6- What is the name of sewage to
which sewage-degrading bacteria
have been added
7- (G) Describe how the oxygen
required by micro-organisms can be
provided during sewage treatment
8- (C) Explain why a range of microorganisms is needed to break down
the range of materials in sewage
Making use of waste
9- ( G) Give two examples of useful
products made from wastes by microorganisms.
-Explain the economic importance of
this technology
- which feature of micro-organisms’
life cycle makes them very useful for
industry.
10- (G) What are fermented fuels?
Name two examples.
11- (G)Explain the advantages of fuels
produced by fermentation compared
with fossil fuels
12-(C) Describe the part played by
bacteria in the process of decay and
recycling of carbon
13- (C) Describe the part played by
bacteria in the process of decay and
recycling of nitrogen
Activated sludge
- spraying out onto small stones (air gaps between stones)
- bubbling air through tanks of activated sludge
- stirring activated sludge
Each type of micro-organism digests one type of waste
substance
- methane (biogas) produced by fermentation of household
or farm waste by decay-micro-organisms. It can be
collected and used as fuel.
- yeast grown on sugar is cheap and can produce food for
animals and humans which is rich in proteins.
- save money for the cleaning up of wastes
- make money by producing food products
- Under suitable conditions, micro-organisms reproduce
very rapidly by asexual means.
- Fuels obtained as products of fermentation
- Alcohol and methane
- fermented fuels will not run out (i.e. renewable) whereas
fossil fuels will run out (i.e. non-renewable)
- using fermented fuels will reduce the use of fossil fuels.
- fermented fuels are not as polluting as fossil fuel
- carbon released in air by
- animal and plant respiration
- rotting animal and plants
- respiration of bacteria feeding on decay materials
- carbon absorbed from air by
- photosynthesis in plants
- carbon in plants “locked up” in plant body or in animal
which feed on plants.
→ without decay-bacteria, carbon locked up in animals and
plants would not be released in the atmosphere
Bacteria transform nitrogen gas or nitrogen-rich wastes
into nitrate which can be used by plants.
2 steps are required:
- 1- conversion of nitrogen wastes and nitrogen gas
to nitrite
- 2- conversion of nitrite to nitrate
1/ Root nodule bacteria in legumes (Nitrogen fixation):
Nitrogen gas → nitrAte
2/ Nitrogen-fixing bacteria in soil (Nitrogen fixation)
Nitrogen gas → nitrAte
3/Decomposers in soil
From decay of plants and animals (including excretion
wastes)
Nitrogen-rich wastes → ammonia
Biotechnology
1- State on what the normal control
of bacteria depends
2- State in general terms how human
can engineer bacteria to make new
substances
3- (C)- State the three different
types of genetic engineering
Explain genetic engineering in terms
of manipulation of chromosomal
materials
1
2
3
4
5
4- (C) State what is the advantage of
genetic engineering for the
production of substances from genes
5- (C) Explain how genetic engineering
can be better than selective breeding
for the production of new organisms
for a particular function
4/ Nitrifying bacteria in soil (Nitrification)
- ammonia → nitrIte
- nitrite → nitrAte
Other bacteria are denitrifying bacteria (Denitrification)
NitrAte in soil → nitrogen gas
Unit 3 – Reprogramming microbes
The information stored in its chromosome.
By transferring a piece of chromosome from another
organism to bacteria.
- adding new genes from other organism
1- Gene from other organism cut by restriction enzymes.
2- In a separate reaction, a ring-like piece of DNA called a
plasmid found in hosting bacteria is cut open.
3- Gene is inserted into plasmid by an enzyme.
4- Plasmid is introduced back into host bacteria.
5- Bacteria allowed to reproduce, produce new desirable
substance from information contained in the new gene.
Obtain large quantities in short time
- faster (no need to wait for plants and animals to
reproduce)
- only the desirable characteristic is passed on.
- possibility of characteristics from different species to
be introduced
6- (G) Give some examples of the
products of genetic engineering and
their applications, e.g. insulin
7- (C) Explain the ever increasing
need for insulin produced by
biotechnology
8- (G&C) How do biological detergent
work? What is their advantages and
limitations?
10- (G) Explain the meaning of
“antibiotics”
11- (C) Explain why a range of
antibiotics is needed in the
treatment of bacterial diseases
12- (C) Explain continuous-flow
processing by immobilized enzymes
13- (C) Describe the advantages of
immobilisation techniques
Product
Insulin
Application
Helps to control blood sugar levels
in diabetics
Growth hormones
Help abnormally small children to
grow
Insulin is a hormone produced in the pancreas. There is an
ever increasing need because world’s population increases
and people live longer
- They breakdown the substrate which is the biological
material in the stain.
- Advantage: work at low temperature:
- saves energy and money
- less damage to clothes
- limitations:
- must be used at low temperature to avoid
denaturation (i.e. destruction) of enzymes
- not useful for non-biological stains, e.g. rust
stains
A chemical produced by a fungus which prevents growth of
a bacteria
Each antibiotic is only active against a particular group of
bacteria → a range of antibiotics is needed against
bacterial diseases which are caused by a wide range of
micro-organisms
Enzymes are immobilised on beads and placed in a reaction
vessel.
The substrate is poured continuously into the vessel, reacts
when in contact with the enzyme and the desired product is
recovered from the bottom of the vessel.
- can run fast
- can run over long periods
- product does not have to be separated from enzymes, i.e.
it saves money and time