easy ppt

1. IGCSE Biology

2.  Biotechnology is the application of biological organisms,
systems or processes to manufacturing industries.
 Genetic engineering involves the transfer of genes from
one organism to an unrelated species.
 Both processes often make use of bacteria.

3.  Brewing of beer
 Baking of bread
 Production of cheese
 Production antibiotics, such as penicillin, from fungi
 Production of industrial chemicals
 Sewage disposal using bacteria .
 Production of biofuels
 Production of biological washing powder
 Production of enzymes from microorganisms
 Production of lactose –free milk
 Genetically modified crops

4.  They have a rapid rate of reproduction
 Their ability to make complex molecules such as proteins.
 Genetic code similar to most of the organisms
 They can be grown using waste products from other industrial processes.
 No ethical concerns:
 Presence of plasmids:

5.  Aerobic respiration
 Anaerobic respiration:

7.  Biofuels are fuels obtained from living matter mostly from
plants.
 Examples:
1. Ethanol made from corn or sugarcane
2. Biodiesel made from algae
3. Biogas/Methane obtained from animal manure

11.  Producing biofuel from algae rather than the is advantageous and
environment friendly because:
 less land is required
 crops can be used as food
 less deforestation thus less habitat destruction
 less disruption to food chains thus greater diversity maintained

12. 1. Less pollution
2. Renewable source of energy as it is a sustainable source
3. Reduces dependence on oil from foreign countries.

13. 1. Expensive to produce:
2. Environmental concerns:
3. Low efficiency as ethanol doesn’t produce as much
energy as the petrol does

15.  Flour, water, salt, oil and yeast are mixed to make dough.
 The dough is repeatedly kneaded - folded and stretched.
 The dough is then left for an hour or two at a temperature of about 27°C
while the yeast does its work.
 Yeast has no enzymes for digesting the starch in flour but the addition of
water activates the amylases already present in flour which digest the
starch to sugar.
 The yeast then ferments the sugar to alcohol and carbon dioxide.The
accumulating CO2 bubbles make the dough rise to about double size
 A protein called gluten gives the dough a sticky, plastic texture, which
holds the bubbles of gas.

16.  The dough is then put straight into baking tins and into an oven at about
200 °C.This temperature:
 makes the bubbles expand more, so bread rises and becomes fluffy
 kills the yeast
 evaporates the small quantities of alcohol
 dough turns into bread.

18.  Pectinase is an enzyme that breaks down pectin, a polysaccharide found
in the cell wall of plants.
 It is extracted from a fungus. And used in juice clarification
 The advantage of pectinase in fruit juice industry is:
 to clarify fruit juice and wine (make it more transparent).
 to speed up extraction of juices from fruits.
 maximise juice extraction and get more profit.

20.  What are Biological washing powders?
 Advantages of using biological washing powders:
1. More effective in cleaning stains than ordinary detergents
2. Needed in small quantities only.
3. They save energy as they can be used to wash clothes at
lower temperatures.
 Disadvantages of using biological washing powders:
1. Temperature needs to be carefully controlled.
2. Biological washing powders may cause allergy in some
people.

23.  Proteases:
 In washing powders for dissolving stains from, e.g. egg, milk
and blood; removing hair from animal hides; cheese
manufacture; tenderising meat.
 Lipases:
 Flavour enhancer in cheese; in washing powders for removal
of fatty stains.
 Pectinases:
 Clarification of fruit juices; maximising juice extraction.
 Amylases:
 Production of glucose from starch.

25. 1. Abdominal cramps or lower abdominal pain
2. Flatulence/Gas
3. Gurgling in the abdomen area
4. Loose stools, diarrhoea
5. Nausea and sometimes vomiting
6. Swelling or feeling of fullness in the abdomen

26.  An immobilized enzyme is an enzyme attached to an inert,
insoluble material—such as glass beads.

27.  Antibiotics are chemical substances used in the treatment and
prevention of bacterial infections.
 Most of the antibiotics we use come from bacteria or fungi that live in the
soil.
 They may either kill or inhibit the growth of bacteria. in the following
different ways.
1. Disrupt the production of the cell wall
2. Rupture their cell walls and cause them to burst open
3. Stops protein synthesis and thus arrest bacterial growth.

28.  Penicillin in produced in large containers called as fermenters

30.  Downstream processing refers to all the processes that occur to the
products after they are removed from the fermenter.
 Downstream processing is necessary
1. to separate and purify penicillin
2. make it free from waste or toxins
3. increases the concentration; distillation process is used to concentrate
the products
4. turning into pills or into usable forms and make them ready for
packaging

31.  The fermenter needs to be regularly sterilised to prevent contamination
by using:
 UV or gamma, radiation or X rays;
 high temperature and high pressure
 by sterilising nutrients and air supply entering the fermenter

33.  To understand the principles of genetic engineering you need to know
something about bacteria, plasmids and restriction enzymes.
1. Bacteria and Plasmids
2. Restriction enzymes
3. Ligase enzymes

34.  Bacteria have circular pieces of DNA called plasmids.
 The plasmids often carry special genes such resistance to antibiotics for
bacteria.

36.  Restriction enzymes are produced by bacteria.They ‘cut’ DNA molecules
at specific sites.These lengths have sticky ends.

39.  Genetic engineering is used to produce:
1. Plants resistance to herbicides or insect pests
2. Plants which can grow in harsh conditions
3. Plants with salt tolerance and drought resistance
4. Seedless watermelons
5. Tomatoes with slow ripening
6. To produce human insulin

41.  Bt Maize is a variety of maize which produces insecticide, so insects die
when they eat their leaves.

42. 1. Plants become resistant and yield increases
2. To grow in a variety of conditions
3. Can be grown everywhere
4. Make more food.
5. Last longer in supermarkets
6. Over come nutrient deficiency

43. 1. Long term effects
2. Not everyone is convincedGM crops are safe-----Allergies
3. Insects may become pesticide resistant
4. Reduces diversity, how?
5. Genes from GM plants may spread into countryside.
6. Transplant genes may get into the natural environment causing the
creation of new plants such as the "superweed" which has become
resistant to herbicide.