Biology: Chapter 3: Enzymes: Immobilizing enzymes

Biology: Chapter 3: Enzymes: Immobilizing enzymes

• Immobilized enzyme: Enzymes attached to an inert, insoluble molecule so they do not get mixed in the solution of substrates and product, which is cost-effective because enzymes are not wasted.
• Using immobilized enzymes means you can re-use the enzymes while the product is enzyme free.

Lactase

1. Lactase is mixed with sodium alginate.
2. Droplets of this mixture is added to a solution of calcium chloride.
3. Each droplet instantly reacts with the calcium chloride to form a jelly bead, containing the enzyme.
4. These beads can be packed into a column, where milk, containing Lactases' substrate, lactose, is poured over them. 
5. Lactase in the alginate beads convert the lactose into glucose and galactose, and trickles down the column, where it can be collected as lactose-free milk.

• This is necessary for producing lactose-free dairy products for people who are lactose-intolerant. Without immobilizing the lactase, the milk would be contaminated with lactase, which we also will be unable to re-use. 
• Another advantage of immobilization is that immobilized enzymes are more tolerant of different pH and temperature changes, because their molecules are held more firmly in place by the alginate they are embedded in and less exposed to the external environment, which means they are less likely to denature.