Immobilised enzymes

Question 1

What are the advantages of using isolated enzymes rather than whole organisms?

Answer 1

Less downstream processing- pure product is produced by using isolated enzymes which can reduce production costs as it is easily separated
More efficient- isolated enzymes can be used at higher concentrations rather than within an organism
More specific- no unwanted enzymes are present
Maximise efficiency- can be given optimal conditions which may not be the same for the whole organism

Question 2

What are the advantages of using immobilised enzymes?

Answer 2

Can be reused- cheaper
Greater tolerance of temperature and pH changes (optimum temperature over a much wider range of temperatures)
Easily separated from products and reactants

Question 3

What are the disadvantages of using immobilised enzymes?

Answer 3

Specialist expensive equipment is required and immobilised enzymes are costly to buy - higher initial start up costs
The process of immobilising an enzyme may reduce its efficiency and ROR

Question 4

What is an immobilised enzyme?

Answer 4

An enzyme which is attached to an insoluble material to prevent freely mixing with the product
The substrate passes over it and is converted to product

Question 5

How can enzymes be immobilised?

Answer 5

Surface immobilisation-
1) Adsorption to an organic carrier (dis- weak bonds so enzymes can be easily lost)
2) Covalent/ ionic bonding to the inorganic carrier (active site of enzyme may be modified in the process, enzymes are strongly bound unlikely to be lost, freely accessible to substrate)

Entrapment
3) In a matrix-
4) Encapsulation in a semi permeable membrane

Dis- diffusion of substrate to and from the product can slow down the reaction