Question

In which type of immobilization, the enzyme will be in a molecular cage?

(a) Adsorption

(b) Covalent binding

(c) Entrapment

(d) Membrane confinement

This question was addressed to me during an online exam.

The question is from Methods of Immobilization in section Immobilized Enzymes Preparation and Kinetics of Enzyme Technology

Answer 1

Correct choice is (c) Entrapment

Explanation: Entrapment is a method in which the enzyme is entrapped within suitable gel or fiber with the covalent bond being formed or not between the enzyme molecule and the matrix. As a result of non-covalent binding, the enzyme will be in molecular cage. This process is known as physical caging. The loading capacity of enzyme in this case is 1g/g gel or fiber. Adsorption method of immobilization involves binding of enzyme to suitable adsorbent which renders it immobile. Immobilization by membrane confinement involves confining the enzyme in aqueous solution within a semipermeable membrane. Covalent binding refers to the method in which the enzyme is linked to the carrier matrix by covalent bond between them.