This reaction is normal but here may bigger,

A essay of schematisation of the chemic shapes:

Ion : a atom or molecule won or lost one or many electrons, we can see two categories :
    Anion : a atom or molecule lost one or many electrons, so it's negative.
    Cation : a atom or molecule won one or many electrons, so it's positive.

It need catalyst for that oxygen to create a reactions with organical mater this catalists are a big enzymes

when a atom lost a electron we speak of redox reaction.

• A oxydase is a enzyme catalyst a reaction of oxydo-réduction so this reaction use a dioxygen molecule (O₂) as acceptor electron.
  
  

  The mitochondria is divided in 5 parts writted in roman numnbers : I,II,III,IV,V,
  each part fabrique is a chemic reaction to creat in part V energy or a molecule of ATP, it's explained below
  In -- the compartment I-- there is the reaction following :
  
  the gen MnSOD mitochondrial create isoenzyme SOD2 in part I of mitochondrie so the reaction following :
  O₂^-.
  
         NDAPH+H⁺ give NAD⁺ and export H⁺↑
  
     H⁺ = ion hydronium so lost is electron (or called proton hydrogen).
     NADP = nicotinamide adénine dinucléotide is a coenzyme oxydo-reduction.
     NADPH or NADPH2 or NADPH+H⁺ mechanism against oxydative stress.
     NADPH+H⁺ is used for biosynthese of fat acids of cholesterol
     SOD2 = Superoxide dismutase 2
    O ₂^-.= anion superoxyde
  
  In the compartment II there is reaction following :
  
  
     FADH₂ → FAD
  
    FAD = Flavine adénine dinucléotide ( protein that contain flavine transportor of electrons, create by vitamine B2 ).
  
  
  in the compartiment III there is reaction following :
  
  this era III (paroi intermédiaire) of mitochondria product
  O₂^-., via SOD1.     exportation of H⁺ ↑
     SOD1 =
    O₂^-. = anion superoxyde (discovered in 1968) anion superoxyde interact with ions H⁺ ( because there is won a electron of him and so H lost 1 electron so H become a proton alone.
  
  In compartment IV there is reaction following :
  
  1/O₂+2H-->H₂O + export de H⁺ (so a oxydase process) H₂O = water O₂ = dioxigène or oxygen
  
  In compartment V there is reaction following :
  
      ATP ↓ - ADP+Pi
  
     Pi = inorganic phosphate
     ADP = adénosine diphosphate is a nucléotide
  
  

  inside the membrane of mitochondria there is the reaction following :
  
     O₂^.→SOD1→H₂O₂↑
    anion superoxyde = O₂^.-
    SuperOxydes Dismutases 1 = SOD (a enzyme antioxydante)
    H₂O₂ hydrogen peroxide
  
  remark de l'étude : SOD1 and SOD2 have studied on mice, it exist SOD3 too

  
  
  • So the cytosolic enzyme CuZnSOD by catalisat(?) give a reaction of anions superoxyde
  
  
  

  In mitochondria there si a reaction by a molecule called catalase ( or CAT ) water from peroxyde hydrogen as this : H₂O₂ →CAT→H₂O ↓ And when the catalase down it's dangerous because peroxyde hydrogène H₂O₂,
  overwhelm catalase mitochondrial and catalase of peroxysome. peroxyde hydrogen give a reaction with iron ions called Fenton reaction
  
  Thz mitochondrial network create many ROS (reactive oxydatif species) so too stress oxydatif :
  this are Ros :
     O₂^-.= anion superoxyde
     OH^- = anion hydroxyde
     CO₃^.- = anion carbonate
     NO₂^- = dioxyde d'azote
     ONOO^- = ion peroxynitrite
  

  
  

  To summary : so we are two way to moment :
     1- what are molecules destroyed by ROS ^per organes.
     2- how to create a depletion of ros in some organes with nor risks for patients.
  then there was some researchs :
    before, we saw reaction of fth1 and aptx on DNA,
    on Cortisol on few next chapters.,
   on glucose don't transform enough ATP, the need of ATP by cell in a another chapter,
    on glutathion reductase(GSR) in a another chapter too.