Glutathione helps protect cells from H2O2 but where is the peroxide coming from?

[whatdidigetinto]

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What is the reaction that makes peroxide in the cell?

 

[GTP]

Nadph oxidase in phagocytes makes oxygen free radicals (respiratory burst). Oxygen free radicals are converted to peroxide by SOD (superoxide dismutase). Oxygen dependent myeloperoxidase adds Cl to the peroxide to make bleach to kill bugs. So u get the h2o2 from the SOD reaction.

 

[whatdidigetinto]

Thank you

 

[Myxedema]

Nadph oxidase in phagocytes makes oxygen free radicals (respiratory burst). Oxygen free radicals are converted to peroxide by SOD (superoxide dismutase). Oxygen dependent myeloperoxidase adds Cl to the peroxide to make bleach to kill bugs. So u get the h2o2 from the SOD reaction.

What you've described is a physiological mechanism. Hydrogen peroxide generated by that way is necessary for oxidative burst. If that hydrogen peroxide were to be removed by catalase, there would have been a defect in phagocyte function.

One of the sources of 'pathological' hydrogen peroxide is aerobic energy metabolism. For example, ETC reactions can produce reactive oxygen species at various levels of reduction. In addition, other enzymatic reactions involving metal ions can produce these radicals. Hydrogen peroxide is one them, as are hydroxyl and superoxide radicals. Now, NADPH oxidase and superoxide dismutase can reduce hydroxyl ions into hydrogen peroxide, but this must be differentiated from the oxidative burst reactions. Ultimately, hydrogen peroxide is removed by catalase/peroxidases and water and oxygen is formed. During this reaction, the electron removed from the hydrogen peroxide is donated to reduced form of glutathione (GSH), forming the oxidized form (GSSG)

 

[GTP]

Yeah that too ^ lol