immobilised enzymes Flashcards
1
Q
state 5 advantages of using immobilised enzymes
A
- more efficient and specific
- no growth medium required
- no need to purify enzyme from product
- easily reused
- decreased sensitivity to ph/temp
2
Q
how is an immobilised enzyme formed?
A
the enzyme is fixed to inert substance and the substrate is passed over it
3
Q
state 3 examples of immobilised enzymes
A
- glucose isomerase = glucose to fructose
- penicillin acylase = formation of semi synthetic penicillin
- lactase = lactose to glucose and galactose
4
Q
why are enzymes immobilised?
A
- used repeatedly
- remains easy to separate substrate and products
5
Q
state 2 disadvantages of immobilising enzymes
A
- slow reaction
- expensive to set up
6
Q
state 4 methods of immobilisation
A
- adsorption
- covalent bonding
- entrapment
- membrane separation
7
Q
describe adsorption
A
- bound to clay, resins or glass beads by non covalent forces
- high rate of reaction
- risk of leakage as weakly bound
8
Q
describe covalent bonding
A
- covalently linked to an insoluble substance
- very little leakage
- only small amount can be immobilised
9
Q
describe entrapment
A
- trapped in a gel or network of fibres
- active sites are accessible
- slow reaction as substrates have to diffuse
10
Q
describe membrane separation
A
- physically separated from substrated by pp membrane
- active sites are accessible
- rate depends on diffusion of substrate and products
