Chapter 22, Problem 22.55QP

Interpretation Introduction

Interpretation:

The class of enzyme dinucleotide diphosphokinase has to be identified.

Concept Introduction:

The enzymes are essentially the biocatalysts present in all living systems. Each enzyme catalyzes a characteristic reaction within the biological system. Enzymes are generally named in accordance with the substrate on which they act. For example, enzyme urease is named by the addition of the suffix–ase to the name of the substrate urea on which this enzyme acts. Similarly, the enzyme sucrase derives its name from sucrose as it hydrolyzes the linkages of sucrose to yield fructose and glucose monomers of disaccharide sucrose.

Based on their specific role and the specific reaction they catalyze enzymes are classified into six major classes. These are as follows:

• Ligases: The enzymes that connect two molecules via covalent bonds are termed as ligases. DNA ligase is one such enzyme.
• Isomerases: The enzymes that catalyze the isomerization reactions are termed as isomerases. For example, triosephosphate isomerase.
• Lyases: The enzymes that catalyze the cleavage of bonds are called lyases. Enzyme fumarase belongs to this category as they cleave the carbon-oxygen bond of malate to convert it reversibly into fumarate.
• Hydrolases: These enzymes catalyze the cleavage of bonds via hydrolysis present in biological systems. Lipase is one such enzyme.
• Transferases: These enzymes are involved in transfer of various functional groups such as methyl, acetyl group, or phosphate group. Dinucleotide diphosphokinase is one such enzyme.
• Oxidoreductases: As the name suggests, these catalyze the oxidation and reduction reactions that occur in living systems. Succinate dehydrogenase is an example of oxidoreductase.