Oxidases and Oxygenases~10 Best Difference

Nov 20, 2023

Oxidases and Oxygenases have a key difference. Oxidase is an enzyme that catalyzes oxidation-reduction reactions, by transferring hydrogen from substrates to oxygen and forming hydrogen peroxide or water. While oxygenases catalyze the incorporation of oxygen directly from molecular oxygen during oxidation.

Protein molecules called enzymes catalyze reactions with biochemicals in living cells. In this way, enzymes increase the speed of reaction because they reduce the activation energies of the reactions. The reactions are therefore carried out at high speed. Some enzymes also catalyze a breakdown of molecules complex into monomers, while others catalyze biomolecule formation from monomers. Oxidase and oxygenase are also two enzymes that can be found in every living thing.

What are Oxygenases?

Figure-no-01: Oxygenases

Oxygenases form a part of the oxidoreductases. They catalyze the incorporation of oxygen atoms into substrates when oxidation occurs. Some reactions include two oxygen atoms, while others only one. Thus, based on the number of oxygen atoms incorporated during the reaction, the enzyme that catalyzes the reaction differs. Mono-oxygenases catalyze the incorporation of one oxygen atom as a hydroxyl group into a substrate. Water is made from the second oxygen atom. Monooxygenases include tryptophan, pyrroles, and carotenes. Dioxygenases, on the other hand, catalyze the incorporation of 2 oxygen atoms to a substratum. Dioxygenases include phenylalanine-hydroxylase (PHH) and tyrosinase.

Oxygenases Types

  • Oxygenases are of two different types:
  1. These enzymes add one oxygen atom to the substrate, and another atom in water.
  2. The enzymes that introduce two oxygen atoms into the substrate are called dioxygenases.

What are Oxidases?

Oxidases, a subset of oxidoreductases, catalyze reactions that involve oxidation and reduction. They participate in oxidation-reduction reactions, transferring hydrogen from the substrate to the oxygen. Oxygen is then converted to water (H2O), or hydrogen peroxide. The result is that complex molecules such as amines and glucose are converted into smaller molecules that are more easily digestible by the human body.

There are also different types of catalase, and the names they have vary depending on what molecule they act upon. Examples of oxidases include cytochrome, monoamine, and ascorbic acid. This reaction shows the action of an oxidase during a reduction-oxidation reaction.

There are different types of oxidases

Different types of oxidases are involved in biological processes. Some common oxidases include:

  • 1. Cytochrome oxidase
  • 2. Lipoxygenase
  • 3. Xanthine oxidase
  • 4. Amine oxidase
  • 5. Polyphenol oxidase

Similarities between Oxidases & Oxygenases?

Oxidases and oxygenases differ in the type of oxidation/reduction they catalyze. Oxidases are enzymes that catalyze hydrogen transfer from a substrate to oxygen, while oxygenases transfer atomic oxygen from O2 onto a surface. Oxygenases come in two different types- monooxygenase and dioxygenase. This is yet another distinction between oxygenases and oxidases.

Differentiating Oxidases and Oxygenases

Let’s now compare oxidases to oxygenases in order to better understand their differences

  • Reaction Catalyzed

Oxidases catalyze oxidation reactions, while oxygenases catalyze reactions that involve the incorporation of oxygen into a molecule. Oxidases are enzymes that catalyze the oxidation reaction, while oxygenases are enzymes that catalyze oxygen incorporation into molecules.

  • The Role of Oxygen

The role of oxygen is another difference. Oxygen is an electron acceptor in oxidases. However, it is also the source of oxygen that gets incorporated into substrates.

  • Different Substrates

The types of substrates that oxidases and oxygenases act upon are also different. Oxidases can act on many substrates including amino acids, carbohydrates, and lipids. Oxygenases act, however, only on a small range of substrates. These include aromatic compounds, steroids, fatty acid, and lipids.

  • The Reactions and their Products

Oxidase and oxygenases also produce different products. Oxidases can produce water or hydrogen peroxide, depending on their electron acceptor. Oxygenases produce oxygenated products.

  • Reaction Mechanism

Oxidase and oxygenases also have different reaction mechanisms. Oxidases transfer electrons directly from the substrate into the electron acceptor. Oxygenases use an indirect method that involves electron transfer to a cofactor, and finally to molecular air.

Table difference:

Aspect Oxidases Oxygenases
Function Catalyze oxidation reactions Catalyze oxygenation reactions
Substrate Specificity Act on a wide range of substrates Act on specific substrates related to oxygenation
Oxygen Requirement Utilize molecular oxygen as a substrate or cofactor Require molecular oxygen as a cosubstrate
Reaction Type Transfer electrons from a substrate to oxygen Incorporate molecular oxygen into a substrate
Enzyme Classification Classified under the oxidoreductase enzyme class Classified under the oxidoreductase enzyme class
Examples Cytochrome oxidase, L-amino acid oxidase Cytochrome P450, dioxygenase
Role in Metabolism Involved in energy production and respiration Participate in various biosynthetic pathways
Coenzymes May require coenzymes for activity May require coenzymes for activity
Cellular Location Found in various cellular compartments Found in various cellular compartments
Importance Essential for metabolic processes Play crucial roles in various biochemical pathways

Oxidases & Oxygenases: Applications

There are many different applications for oxygenases and oxidases. These applications include:

  • Medical Field

In medicine, oxygenases and oxidases can be used to diagnose diseases. The presence of certain oxygenases in the urine can be an indicator of medical problems. The production of pharmaceuticals also uses oxygenases.

  • Food Industry

In the food industry, oxygenases and oxidases can be used to enhance the shelf-life and quality of products. In the food industry, polyphenol oxidase can be used to brown fruits and vegetables. Lipoxygenase produces flavors.

  • Bioremediation

In bioremediation, oxygenases can be used to reduce harmful pollutants in the environment. Dioxygenases, for example, are used in soil contamination to break down polycyclic hydrocarbons.

  • Agriculture

In agriculture, oxidases and oxygenases can be used to combat pests and diseases. In the treatment of plant pathogens and the manufacture of natural insecticides, polyphenol oxidase can be used.

Summary – Oxidases vs Oxygenases

Oxidases, and oxygenases, are types of oxidoreductases that catalyze oxidation-reduction reactions. Oxidases are enzymes that catalyze the transfer of hydrogen from a substrate to oxygen in an oxidation-reduction reaction. Oxygenases, on the other hand, catalyze direct incorporation from O2 into a substrate. This is why the main difference between oxygenases and oxidases.