An example of oxidation - reduction enzyme is

Analysis

The question asks for an example of an enzyme that catalyzes oxidation-reduction (redox) reactions. In biochemistry, enzymes are classified based on the type of reaction they catalyze.

Concept Explanation

Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are categorized into six major classes by the International Union of Biochemistry and Molecular Biology (IUBMB):

1. Oxidoreductases: These catalyze oxidation-reduction reactions (the transfer of electrons or hydrogen atoms from one molecule to another). Examples include dehydrogenases, oxidases, and peroxidases.
2. Transferases: These transfer functional groups (e.g., methyl or phosphate groups).
3. Hydrolases: These catalyze the breaking of chemical bonds by the addition of water (hydrolysis). Examples include amylase, protease, and lipase.
4. Lyases: These break bonds by means other than hydrolysis or oxidation.
5. Isomerases: These catalyze structural changes within a single molecule.
6. Ligases: These catalyze the joining of two molecules.

Step-by-Step Solution

• Amylase (Option A): This is a hydrolase that breaks down starch into sugars.
• Protease (Option B): This is a hydrolase that breaks down proteins into peptides or amino acids.
• Lipase (Option C): This is a hydrolase that breaks down fats (lipids) into fatty acids and glycerol.
• Dehydrogenase (Option D): This enzyme removes hydrogen atoms from a substrate, which is a fundamental process in biological oxidation. Therefore, it belongs to the class of oxidoreductases.

Since the question specifically asks for an oxidation-reduction enzyme, dehydrogenase is the correct classification.

Exam Tip

Remember the suffix "-ase" usually denotes an enzyme. To distinguish them:

• If it breaks bonds using water, it is a Hydrolase (Amylase, Protease, Lipase).
• If it involves moving electrons or hydrogen, it is an Oxidoreductase (Dehydrogenase).