Using immobilised enzymes

Question 1

What is enzyme immobilisation?

Answer 1

Involves attaching/enclosing enzyme onto solid support/matrix

Allows for reuse of enzyme + increase stability

Question 2

Whta are the main methods of enzyme immobilisation?

Answer 2

Binding: Enzyme bound to insoluble support material (cellulose/collagen fibres) by covalent/ionic bonds

Adsorption: Enzyme adsorbed ont surface of insoluble support materials

Entrapment: enzyme trapped in matrix (silica gel) or microcapsule

Encapsulation: enzyme isolated by partially permeable membrane (within semi-permeable alginate beads)

Question 3

What are the advantages of using immobilised enzymes?

Answer 3

**Cost-effective: **immobilising enzymes = allows for reuse of enzymes, reducing need to purchase new enzymes

Product purity: immobilisation produce enzyme-free products –>avoid contamination of products with enzyme

Improve stability: more tolerant of temp + pH changes than enzyme in solution –> more stable + less likely to denature

Question 4

What are the disadvantages of using immobilised enzymes?

Answer 4

Higher inital costs: materials/bioreactors = more expensive than free enzymes

Reduced enzyme activity: immobilisation reduce enzyme efficiency

Technical problems: reactor system complex + prone to more technical problems

Question 5

Why does lactose contain immobilised enzymes?

Answer 5

Lactose-free milk created by removing lactose by immobilising enzymelactase –> breaks down into glucose + galactose.

Question 6

What are the steps in immobilising lactase?

Answer 6

1. Lactase enzyme attached to aligante beads to immobilise
2. Lactase containing beads packed into column
3. Milk allowed to flow through column
4. Lactase hydrolyses lactose inmilk into glucose + galactose –> produce lactose free milk
5. Lactase remains in column –>more milk processed continually
6. Lactose free milk used to make dairy products for lactose-intolerant people