Question

What does the following diagram represent?

(a) Adsorption

(b) Entrapment

(c) Microenvironment and Macroenvironment

(d) Covalent binding

The question was posed to me in an international level competition.

This interesting question is from Kinetics of Immobilized Enzymes topic in chapter Immobilized Enzymes Preparation and Kinetics of Enzyme Technology

Answer 1

The correct answer is (c) Microenvironment and Macroenvironment

The explanation: The diagram below represents a cross-section of an immobilized enzyme particle showing micro and macro-environment.

The triangle represents the enzyme molecules. The internal solution with part of the surrounding solution is referred to as microenvironment. This is influenced by the surface characteristics of the immobilized enzyme. Partitioning of substances will occur between these two environments. Substrate molecules (S) must diffuse through the surrounding layer (external transport) as well as the pores (internal transport) in order to utilize all of the enzyme available.