All of the following enzymes may contribute in generating free oxygen radicals within neutrophils for killing intracellular bacteria, except -

Ans. is `a'i.e. Superoxide dismutaseGlutathione peroxidase is primarily a scavanger of free radicals and catalyzes free radical breakdown (does not generates free radicals). Superoxide dismutase is also a scavenger of free radical and conves superoxide into H202. However, it is indirectly involved in generation of free radicals (see previous explanation). So, you keep in mind that SOD is primarily an antioxidant (free radical scavenger). But for this question, we can consider SOD to be involved in generation of free radicals (indirectly)as we have better option for our answer (glutathione peroxidase).