Iron Enzymes and Catalase Mechanisms

Study Notes

Metal Activated Enzymes: Iron Enzymes

Iron is an essential element in redox reactions in plant metabolism.
Catalases are heme enzymes.
Catalases catalyze the disproportionation of hydrogen peroxide.
Harmful H₂O₂ is decomposed into O₂ and H₂O.
The reaction is: 2H₂O₂ → O₂ + 2H₂O.

Catalase Mechanism

Catalase is an enzyme with a systematic name "donor hydrogen peroxide oxidoreductase".
It catalyzes the chemical reaction: (1) to release oxygen.
It's a strong catalyst using hydrogen peroxide as the donor.
It uses a prosthetic group, containing haematin or related compounds.
These enzymes catalyze the decomposition of peroxidases like hydrogen peroxide, breaking it down into oxygen and water.
This process avoids buildup of toxic peroxides.

Catalase as a Donor

Catalase has a donor role, receiving or accepting electrons.
The enzyme acts as an oxidising agent in some cases.

Chemical Reaction

The chemical reaction H₂O₂ is converted to products O₂ and H₂O.
Peroxide is the donor and is used as an oxidising agent by the enzyme.
The chemical reaction releases oxygen.
This chemical equation is 2H₂O₂ → O₂ + 2H₂O.

Description

Explore the role of iron in activated enzymes, particularly catalases, in plant metabolism. This quiz covers the chemical reactions involving hydrogen peroxide and the catalytic functions of catalase. Discover how catalase decomposes harmful H₂O₂ into harmless water and oxygen, acting as a crucial enzyme in preventing toxin buildup.