Immobilised enzymes

• Immobilised enzymes can't move, they are attached to an inert (unreactive) support
• What are the two methods used to immobilise enzymes?

  -entrapment or encapsulation in sodium alignate beads

  -binding or cross-linking to cellulose fibres
• What are the examples of cross-linking enzymes to cellulose fibres?

  -Clinistix (used to test for glucose in urine) -> includes a cellulose pad with enzyme attached

  -Biosenser (used to measure blood glucose in diabetics) -> has a digital display of blood glucose concentration, transducer to produce a current and cellulose pad for blood
• What are the advantages of using immobilised enzymes?

  -> immobilised enzymes can be separated from the product:

  -this means the product is not contaminated with enzymes that people can be allergic to

  -the enzyme is ready to use and therefore reduces cost of industrial processes
• What are the advantages of using immobilised enzymes?

  -> immobilised enzymes are more stable, they are less affected by changes in temperature and pH, working over a wide range and denaturing at higher temperatures

  -immobilisation 'protects' the enzyme against changes in pH or temperature, providing a barrier between the enzyme and the environment

  -as enzymes denature at higher temperatures, reactions can be carried out at higher temperatures, so a faster rate
• What are the disadvantages of using immobilised enzymes?

  -> the enzymes need immobilising

  -takes time

  -needs more chemicals, expensive
• What are the disadvantages of using immobilised enzymes?


  -> the method of immobilisation may make it harder for enzyme-substrate complexes to form

  -the initial and/or maximum rate may be lowered