Chapter 3

*Enzymes Part 5

*Immobilizing Enzymes*Using enzymes

commercially can be very expensive

*Being able to reuse enzymes solves this problem

* Immobilized enzymes reusable, not lost in commercial product

*Definition: Enzymes that have been fixed to a surface or within a bead of agar gel

*Commercial application of enzymes

*Medicine

*Food technology

*Industrial processing

*How to Make an Immobilized Enzyme*Use alginate beads

*Create these bead bye mixing enzymes with a sodium alginate solution

*Take tiny droplets from this sodium alginate mixture and add them to a solution of calcium chloride

*Sodium Alginate and Calcium Chloride react to form a jelly

* Jelly turns each droplet into a tiny “bead”

* Each bead contains an enzyme that is now “immobilized”

*Example*Immobilization of LACTASE

enzyme used to make Lactose-FREE milk

*Use alginate beads

*Run substrate (milk) through the beads

*Lactase in beads hydrolyzes the lactose (disaccharide) substrate in milk into glucose and galactose monosaccharides

*Milk goes all the way through the column and collects into apparatus

*Collected milk is now lactose-free and is NOT contaminated with the enzyme

*Advantages of Immobilized Enzymes1. Easy removal of product from enzyme

*Without immobilized enzymes:

*Enzymes would be mixed in solution with substrate

*When product is made, the product would have to be separated from the enzymes in solution (costly and time consuming)

*Enzymes lost during removal process

2. Immobilized enzymes tolerant to changes in temperature and pH

*More tolerant than enzymes used in solution

*Due to protective environment of alginate beads

*Enzymes do not denature easily