How is superoxide radical produced in the mitochondria?
Superoxide produced in mitochondria is generated by electrons leaking from the electron transfer system, which is located in the inner membrane of mitochondria. These electrons are then captured by molecular oxygen and become superoxide.
How superoxide radical is formed?
Superoxide, which is an anion radical, is produced by the one-electron reduction of molecular oxygen. The levels of superoxide are kept low by effective compartmentalization of the sequential reductions of oxygen and by extensive expressions of superoxide dismutases with high affinities for superoxide.
What is the enzyme that converts superoxide radicals to hydrogen peroxide?
Superoxide dismutase
Superoxide dismutase (SOD) is a ubiquitous antioxidant enzyme that catalytically converts the superoxide radical to hydrogen peroxide (H2O2).
What is the function of superoxide radicals?
Small increases in levels of mitochondrially produced superoxide radicals have a protective effect during H2O2-induced stress, and in response to H2O2, the wild-type strain increases superoxide radical production to activate this defense mechanism.
Where do superoxide ions and hydrogen peroxide originate?
Superoxide (O2˙̄)2 and hydrogen peroxide (H2O2) are produced by leaks of electrons from donor redox centers of the mitochondrial electron transport chain and associated metabolic enzymes to cause either one-electron or two-electron reduction of oxygen (1, 2).
What is the difference between peroxide and superoxide?
Peroxide and superoxide are oxides containing oxygen atoms. The main difference between peroxide and superoxide is that the oxidation state of oxygen in peroxide is -1 whereas the oxidation state of oxygen in superoxide is -1/2.
How does superoxide become hydrogen peroxide?
The redox-active metal in each enzyme (Cu2+ or Mn3+) is reduced by the first superoxide molecule yielding molecular oxygen. A second superoxide molecule is then reduced to hydrogen peroxide by the metal ion. The reaction is limited only by the diffusion of superoxide to the enzyme (Fridovich 1995).
What is the function of SOD?
Superoxide dismutases (SODs) constitute a very important antioxidant defense against oxidative stress in the body. The enzyme acts as a good therapeutic agent against reactive oxygen species-mediated diseases.
What is superoxide and peroxide?
Both peroxides and superoxides are known to be oxides that contain oxygen atoms. In a peroxide, the oxidation state of oxygen is known to be -1 whereas in a superoxide, the oxidation state of oxygen is known to be -1/2.
How do you identify hydrogen peroxide and Superoxides?
If you want to distinguish oxide, superoxide and peroxide ions, generally you can use their X-ray structure well. Oxide is a single oxygen ion, superoxide and peroxide is O−O with approximate bond distance of 1.33 and 1.49 A respectively.