biotechnology

Question 1

what is biotechnology

Answer 1

use of living organisms or parts of living organisms in industrial process - could be to produce food, drug or to remove toxic materials = bioremediation. Biotechnology also encompasses gene technology, genetic modification, selective breeding, cloning, use of enzyme in industry and immunology.

Question 2

why must we ensure, that we prevent the growth of unwanted bacteria?

Answer 2

• they will compete, with culture m/o for nutrients and space and therefore reduce yield of useful product.

Question 3

why do we not wanted unwanted bacteria?

Answer 3

• produce toxins and chemical and which may contaminate the product, destroy cultured m/o and their products. In food/ medicine if contamination occurs waste/toxic products must be discarded.

Question 4

what are primary metabolites?

Answer 4

e.g. alcohol from saccharomyces cerevisiae.

Question 5

what is continuous fermentation

Answer 5

• used when primary metabolite is the required product -> this is a product synthesised in normal metabolism when the m/o is actively dividing.

Question 6

describe the process of continuous

Answer 6

• sterile nutrient medium is continually added to the culture, once it reaches the exponential point of growth.
• culture broth is continually removed. (medium, m/o, waste and desired product) so culture volume in fermenter is constant.

Question 7

what are secondary metabolites

Answer 7

e.g. antibiotics from penicillium Crysogenum

Question 8

what is batch fermentation

Answer 8

• when secondary metabolites is required product = product synthesised only when there is limited nutrients availability in stationary phase.
• m/o are inoculated into a small. volume of sterile medium.
• as growth takes place, nutrients are used up and both new biomass and waste products, build up.
• as the culture reaches stationary phase overall growth ceases, but during this phase the m/o often produce the desired end products as secondary metabolites.

Question 9

know the comparasion, between batch and continuous production , of bread

Answer 9

yeast

Question 10

name the type of m/o used to produce cheese

Answer 10

lactoballiclus (bacteria)

Question 11

name the type of m/o used to produce human insulin

Answer 11

coli. (Bacteria)

Question 12

name the type of m/o used to produce penicillin

Answer 12

fungus

Question 13

name the type of m/o used to produce beer

Answer 13

yeast

Question 14

what happens during the process of malting

Answer 14

barley grains, germinate and starch is broken down in maltose

Question 15

what happens during the process of rising (proving)

Answer 15

carbon dioxide is produced

Question 16

what happens during the process of fermentation

Answer 16

yeast, added to cooled wort (anaerobic respiration) , which produces ethanol and carbon dioxide.

Question 17

bioremediation

Answer 17

removal of toxic materials, from polluted sources. e.g. heavy metals + breakdown of hydrocarbons in crude oil, petrol.

Question 18

understand the aseptic techniques on page 15

Question 19

what is an immobilised enzyme

Answer 19

enzymes are held in place, are not free to diffuse through the solution.

Question 20

what are the 4 methods of immobilised enzyme

Answer 20

• adsorption.
• surface immobilisation.
• entrapment.
• encapsulation.

Question 21

what is adsorption

Answer 21

• enzyme bound to supporting surface by a combination of hydrophobic and ionic links.
• suitable surfaces include, clay, porous carbon, glass beads and resin.

Question 22

what is surface immobilisation

Answer 22

• enzymes are bonded to supporting surface such as clay using covalent or ionic bonds. Enzymes are bonded using a cross linking agent which may also link them in a chain.

Question 23

what is surface entrapment

Answer 23

• enzymes are trapped in a matrix. e.g. polysaccharides (cellulose mesh) that does not allow free movement.
• calcium alginate beads are often used in school.

Question 24

what is encapsulation

Answer 24

• encapsulation in microcapsules made of semi permeable membrane. (membrane separation).

Question 25

what are the advantages of adsorption.

Answer 25

- simple, + cheap to set up. - enzyme active site, is exposed + accessible to the substrate.

Question 26

what are the disadvantages of adsorption

Answer 26

- enzyme molecules, can detach from matrix or carrier easily. - active site distorted by bonds connecting the enzymes to the carrier.

Question 27

what are the advantages of surface immobilisation

Answer 27

enzyme molecules are much less likely to detach from matrix.

Question 28

what are the disadvantages of surface immobilisation

Answer 28

- more expensive to set up, compared to adsorption. - stronger covalent bonds, distort, active site.

Question 29

what are the advantage of entrapment

Answer 29

- enzyme shape, unaffected by entrapment.

Question 30

what are the disadvantages entrapment

Answer 30

- substrate must diffuse in + products, must diffuse out. - only works with small reactant or products.

Question 31

what are the advantages of encapsulation

Answer 31

- easy to setup/ cheap to set up. - membrane, has no effect, on shape of enzyme.

Question 32

what are the disadvantages of encapsulation

Answer 32

- substrate. must diffuse in + products must diffuse out. - slow substrate diffusion, into bed through membrane, is limited by presence of product.