Chapter 19, Problem 19.24UKC

Interpretation Introduction

Interpretation:

The two types of bonding which will occur in the bonding of the enzyme-substrate complex should be given with dotted lines.

Concept Introduction:

Enzyme:

• It is a protein or a molecule which can act as a catalyst for a biological reaction.
• Does not affect the equilibrium point of the reaction.
• Active site of the enzyme is the region where the reaction takes place.
• Enzyme’s activity can be specific which means the activity is limited to a certain substrate and a certain type of reaction and it is referred to as specificity of the enzyme.

Hydrogen bonding: It is an unusual strong intermolecular force occurs between a hydrogen atom and an electronegative atom like nitrogen, oxygen or fluorine. It occurs in both water and ammonia

Answer to Problem 19.24UKC

Explanation of Solution

Enzymes are three dimensional molecule with a catalytic site into which the substrate can fit. The enzymes are said to be so specific in their action because the activity is limited to a certain substrate and a certain type of reaction and it is referred to as specificity of the enzyme. It can be said that few molecules have the appropriate shape and functional groups to fit into the catalytic site.

Given in the diagram a dipeptidase enzyme and the substrate to form the enzyme-substrate complex. Different types of bonding may occur between the enzyme and the substrate to form the enzyme-substrate complex.

Hydrogen bonding is the attraction between a hydrogen atom and an electronegative atom and it can be considered as a special type of dipole-dipole interaction. The oxygen atom in the substrate can make hydrogen bond with hydrogen in the enzyme.

Salt bridges are formed between oppositely charged residues that are nearby to experience electrostatic attraction. Here, salt bridge is formed between the anionic carboxylate ion ${\text{RCOO}}^{\text{-}}$ and the cationic ammonium ion ${\text{RNH}}_{\text{3}}{}^{\text{+}}$

The bonding is shown below:

Conclusion

The two types of bonding which will occur in the bonding of the enzyme-substrate complex is given with dotted lines.