How are enzymes immobilised

Question 1

Advantages and disadvantages of adsorption to inorganic carrier

e.g. cellulose or silica

Answer 1

Advantages

1) Simple and cheap to do
2) Can be used with many different processes
3) Enzymes are accessible to the substrate and their activity isn’t changed

Disadvantages
1) Enzymes can be lost from the matrix relatively easily

Question 2

Advantages and disadvantages of covalent or ionic bonding to inorganic carrier

Covalent - amino, hydroxyl

Ionic - polysaccharides

Answer 2

Advantages

1) Cost varies
2) Enzymes are strongly bound and unlikely to be lost
3) Enzymes are accessible to the substrate
4) pH and substrate concentration has little effect on enzyme activity

Disadvantages

1) Cost varies
2) Active site of the enzyme might be modified in the process making it less effective

Question 3

Advantages and disadvantages of entrapment in matrix

Polysaccharides

Answer 3

Advantages
1) Widely applicable to different processes

Disadvantages

1) Expensive
2) Difficult to entrap
3) Diffusion of the substrate to and from the product from the active site can be slow and hold up the reaction
4) Effect of entrapment on enzyme activity is variable

Question 4

Advantages and disadvantages of entrapment in microcapsule

Semi permeable membrane

Answer 4

Advantages

1) Relatively simple to do
2) Relatively small effect on enzyme activity
3) Widely applicable to different processes

Disadvantages

1) Relatively expensive
2) Diffusion of the substrate to and from the active site can be slow