biotechnology Flashcards
what is biotechnology
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.
why must we ensure, that we prevent the growth of unwanted bacteria?
- they will compete, with culture m/o for nutrients and space and therefore reduce yield of useful product.
why do we not wanted unwanted bacteria?
- 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.
what are primary metabolites?
e.g. alcohol from saccharomyces cerevisiae.
what is continuous fermentation
- used when primary metabolite is the required product -> this is a product synthesised in normal metabolism when the m/o is actively dividing.
describe the process of continuous
- 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.
what are secondary metabolites
e.g. antibiotics from penicillium Crysogenum
what is batch fermentation
- 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.
know the comparasion, between batch and continuous production , of bread
yeast
name the type of m/o used to produce cheese
lactoballiclus (bacteria)
name the type of m/o used to produce human insulin
coli. (Bacteria)
name the type of m/o used to produce penicillin
fungus
name the type of m/o used to produce beer
yeast
what happens during the process of malting
barley grains, germinate and starch is broken down in maltose
what happens during the process of rising (proving)
carbon dioxide is produced
what happens during the process of fermentation
yeast, added to cooled wort (anaerobic respiration) , which produces ethanol and carbon dioxide.
bioremediation
removal of toxic materials, from polluted sources. e.g. heavy metals + breakdown of hydrocarbons in crude oil, petrol.
understand the aseptic techniques on page 15
what is an immobilised enzyme
enzymes are held in place, are not free to diffuse through the solution.
what are the 4 methods of immobilised enzyme
- adsorption.
- surface immobilisation.
- entrapment.
- encapsulation.
what is adsorption
- enzyme bound to supporting surface by a combination of hydrophobic and ionic links.
- suitable surfaces include, clay, porous carbon, glass beads and resin.
what is surface immobilisation
- 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.
what is surface entrapment
- 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.
what is encapsulation
- encapsulation in microcapsules made of semi permeable membrane. (membrane separation).
what are the advantages of adsorption.
- simple, + cheap to set up.
- enzyme active site, is exposed + accessible to the substrate.
what are the disadvantages of adsorption
- enzyme molecules, can detach from matrix or carrier easily.
- active site distorted by bonds connecting the enzymes to the carrier.
what are the advantages of surface immobilisation
enzyme molecules are much less likely to detach from matrix.
what are the disadvantages of surface immobilisation
- more expensive to set up, compared to adsorption.
- stronger covalent bonds, distort, active site.
what are the advantage of entrapment
- enzyme shape, unaffected by entrapment.
what are the disadvantages entrapment
- substrate must diffuse in + products, must diffuse out.
- only works with small reactant or products.
what are the advantages of encapsulation
- easy to setup/ cheap to set up.
- membrane, has no effect, on shape of enzyme.
what are the disadvantages of encapsulation
- substrate. must diffuse in + products must diffuse out.
- slow
substrate diffusion, into bed through membrane, is limited by presence of product.
