Question

Which of the following reactive species does not play a role in the initiation of lipid peroxidation?

a) Nitric oxide

b) All of the above plays a role in the initiation of lipid peroxidation

c) Superoxide radical

d) Triplet oxygen

e) Iron ion

Answer 1

a) Nitric oxide : It play role in the initiation of lipid peroxidation. It react with the superoxide radical to form peroxynitrate which is short lived oxidant species that is potent inducer of cell death.

b) All of the above plays a role in the initiation of lipid peroxidation : It is wrong option because triplet oxygen does not play a role in the initiation of lipid peroxidation.

c) Superoxide radical (O₂^*): It helps in the reduction of hydrogen peroxide (H₂O₂) and hydroxyl radical (HO^*). It is formed by the one electron reduction of molecular oxygen.

d) Triplet oxygen : It does not involve in the initiation of lipid peroxidation. It is singlet oxygen that involve which is formed by the triplet-singlet energy transfer of ³C^* to molecular oxygen.

e) Iron ion : Ferrous ion (Fe⁺²) involve in the reduction of H₂O₂ . Bicyclic endoperoxides react with this ferrous ion in order to produce alkoxyl radicals that react with oxygen later.