Biotechnology and genetic modification

Question 1

what is biotechnology

Answer 1

the application of biological organisms, systems or processes to manufacturing and service industries

Question 2

what is genetic engineering

Answer 2

changing the genetic material of an organism by removing, changing or inserting individual genes

Question 3

why are bacteria useful in biotechnology and genetic engineering

Answer 3

-rapid reproduction rate
- ability to make complex molecules
- few ethical concerns over their manipulation and growth
- presence of plasmids (=small circular pieces of DNA, additional to the bacterial chromosome, found in the cytoplasm of bacteria. They are used as vectors for the transfer of genes.
- rather ‘low’cost and ‘little’space needed
-genetic code is shared with all other organisms

Question 4

examples of genetic engineering

Answer 4

1. Insertion of human gene into bacteria for production of human proteins e.g. insulin
2. Insertion of genes into crop plants to confer resistance to herbicides thus the field can be sprayed with herbicide and only the weeds but not the crop plants will die
3. Insertion of genes into crop plants to confer resistance to insert pests e.g. insertion of the Bt toxin gene. Bt toxins kills insect pests
4. Insertion of gene into crop plants to improve nutritional qualities e.g. probvide additional vitamins e.g. golden rice contains additional vitamin A

Question 5

benefits of genetic engineering

Answer 5

• higher yield
• reduce use of pesticides
• less food wastage
• new areas of cultivation if plants can tolerate extreme environmental conditions
• higher nutritional value
  medicinial products
• more predictable results

Question 6

hazards of genetic engineering

Answer 6

• spread of transgene to all- type population e.g. herbicide resistant gene – superweeds
• insects resistant to toxins
• non- targeted organism killed (e.g. butterfly from Bt toxin
• long-term effects unknown
• allergies
  -escape engineered bacteria
• unfair to smaller farmers

Question 7

conditions in fermenters

Answer 7

• fermenter contains the fungus/bacterium in a medium with sugars and amino acids (nutrient supply)
• pH and temperature are adjusted (optimal for microorganisms)
• air is blown through the solution to provide o2 for aerobic respiration (excepts if anaerobic respiration is needed)
• sterile conditions
• stirrers continuously stir the mixture

Question 8

what happens to the product in the fermenter

Answer 8

the microorganism often secretes the product we need (e.g. enzyme, antibiotic) into the medium. The product is extracted and purified so that it becomes more concentrated and to remove wastes/ toxins (=is then packed to a medicine)
— if the product remains intracellularly the microorganisms are isolated and crushed to extract it

Question 9

applications of biotechnology

Answer 9

Anaerobic respiration in yeast and production of pencillin and enzymes in industry

Question 10

what is anaerobic respiration used for

Answer 10

used in break-making and in the production of ethanol as a biofuel
glucose—-> ethanol + carbon dioxide + energy

Question 11

how is biofuel produced

Answer 11

-ethanol is produced for use as biofuel
-process called alcoholic fermentation
- yeast grown in fermenters without O2 so it respires anaerobically and produces ethanol
- if the ethanol concentration in the medium exceeds 8-9% the yeast dies

Question 12

how is bread-making done

Answer 12

• flour, sugar, water, salt and yeast are mixed to produce dough
• dough is kept at 28C and the yeast ferments the sugar
• the produced CO2 is trapped by sticky proteins in the dough (e.g. gluten) causing the dough to rise. Trapped CO2 bubbles make the break supply
• the dough is baked at 200C. So, the yeast is killed, ethanol evaporates and the outer surface hardens forming a crust

Question 13

What are antibiotics

Answer 13

antibiotics are either bacteriocidal (=kills bacteria) or bacteriostatic (= stops bacteria from reproducing)
- antibiotics inhibit processes that are specific to bacteria, e.g cell wall formation or bacterial translation. Thus, they do not affect the human cells

Question 14

what is penicillin

Answer 14

penicillin is an antibiotic
- it is naturally produced by the fungus Penicillium
- it prevents cell wall formation

Question 15

how is penicillium made in industry

Answer 15

Penicillium is grown in fermenters at 26C, pH 5-g and with air blown. The fungus secretes the antibiotic into the medium

Question 16

what are enzymes used for

Answer 16

• are needed for several industrial processes or in products
• are produced using bacteria or fungi grown in fermenters

Question 17

what is pectinase

Answer 17

pectinase is used in fruit juice production
- the enzyme pectinase is extracted from fungi
- it breaks down pectin and other carbohydrates to clarify the juice (= make it more transparent)

Question 18

what are biological washing powders

Answer 18

• they contain proteases (break down proteins) and lipases (breakdown lipids)
• they remove stains by digesting the large and insoluble protein and fat molecules into small, soluble molecules, which can pass out of the cloth
• they save energy because clothes are washed at lower temperatures (higher temperature will denature the enzymes)

Question 19

what is lactose

Answer 19

disaccharide in milk and dairy

Question 20

what is lactase

Answer 20

enzyme that breaks down lactose

Question 21

use of lactase in the production of lactose- free milk

Answer 21

• some people are lactose intolerant = don’t produce enough lactase so cant digest lactose. Lactose stays in the gut and is fermented by bacteria, causing pain, flatulence and diarrhoea
• lactase is produced by fermenting yeast and is used to make lactose- free milk
• lactase is either added to milk or it is immobilised on the surface of beads and milk passed over the beads
• advantages of using immobolised enzymes: the milk foes not contain the enzyme and the enzyme can be reused