Industrial enzymes

HideShow resource information
  • Created by: Steff06
  • Created on: 18-06-16 10:32
What features of enzymes make them so useful in industrial processes?
Specificity - enzymes can catalyse reactions between specific chemicals. Fewer by-products are formed. Temperature of enzyme action - most function well at lower temperatures saving money.
1 of 26
What is downstream processing?
The extraction of enzyme from the fermentation mixture.
2 of 26
What must happen in order for the product of a enzyme-controlled reaction to be generated?
Enzyme and substrate must be able to collide and form enzyme-substrate complexes.
3 of 26
How is this achieved?
By mixing quantities of substrate and isolated enzymes together under suitable conditions for the enzyme to work. The product then has to be extracted.
4 of 26
Why would we use immobilised enzymes?
So they can catalyse the enzyme-controlled reaction but do not mix freely with the substrate as they normally would in a cell/isolated system.
5 of 26
What are the advantages of using immobilised enzymes?
Downstream processing costs will be low as enzymes are not present with products. Enzymes immediately available for reuse and immobilised enzymes are more stable as the immobilising matrix protects the enzyme processes.
6 of 26
What are the disadvantages of using immobilised enzymes?
Requires additional time, equipment and materials so is more expensive. Can be less active as they do not freely mix with the substrate. Contamination is costly to deal with.
7 of 26
What does the precise method used for a particular process depend on?
Ease of preparation, cost, relative importance of enzyme leakage and efficiency.
8 of 26
What are the 4 methods for immobilising enzymes?
Adsorption, covalent bonding, entrapment, membrane separation.
9 of 26
What do adsorption and covalent bonding involve?
Involve binding enzymes to a support.
10 of 26
How do entrapment and membrane separation secure the enzymes?
Hold them in place instead of binding.
11 of 26
Describe the process of adsorption
Enzyme molecules are mixed with the immobilising support and bind to it through hydrophobic interactions and ionic links.
12 of 26
What are examples of adsorption agents?
Porous carbon, glass beads, clays and resins.
13 of 26
How does adsorption give high reaction rates?
The enzyme molecules are held so their active site is not changed and is displayed.
14 of 26
What is a problem with adsorption?
Because the bonding forces are not particularly strong, enzymes can become detached (leakage).
15 of 26
How are enzymes covalently bonded?
Bonded to a support often by covalently linking enzymes together to an insoluble material using a cross-linking agent.
16 of 26
What are examples of cross-linking agents?
Gluteraldehyde and sepharose.
17 of 26
What is the consequence of the binding being strong?
There is very little leakage of enzyme from the support.
18 of 26
What is a problem of covalently bonding?
It does not immobilise a large quantity of enzyme.
19 of 26
What can the enzymes be trapped in?
In a gel bead or a network of cellulose fibres.
20 of 26
How are the enzymes trapped?
Trapped in their natural state (not bound to another molecule so their active sites will not be affected).
21 of 26
How can reaction rates be reduced?
Because substrate molecules need to get through the trapping barrier.
22 of 26
What does this mean in terms of the active site?
The active site is less easily available than with adsorbed or covalently bonded enzymes.
23 of 26
How does membrane separation work?
Enzymes can be physically separated from the substrate mixture by a partially permeable membrane.
24 of 26
Why can the reaction take place?
Because substrate molecules are small enough to pass through the membrane and product molecules are small enough to pass back through the membrane.
25 of 26
What have immobilised penicillin acyclase enzyme reactors been used to convert?
Convert the antibiotic penicillin into amino penicillanic acid on a large scale.
26 of 26

Other cards in this set

Card 2

Front

What is downstream processing?

Back

The extraction of enzyme from the fermentation mixture.

Card 3

Front

What must happen in order for the product of a enzyme-controlled reaction to be generated?

Back

Preview of the front of card 3

Card 4

Front

How is this achieved?

Back

Preview of the front of card 4

Card 5

Front

Why would we use immobilised enzymes?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Microbiology and fungi resources »