<prompt> Respiratory burst in neutrophils occurs due toNADPH oxidaseNADP oxidaseFADH2 oxidaseFAD  <response>: When the cell membrane-bound enzyme NADPH oxidase is activated, with the production of toxic oxygen metabolites. The combination of the toxic oxygen metabolites and the proteolytic enzymes from the granules makes the neutrophil a very effective killing machine. Activation of NADPH oxidase is associated with a sharp increase in O2 uptake and metabolism in the neutrophil the respiratory burst and generation of O2- by the following reaction: NADPH H 2O2 - NADP 2H 2O2- O2- is a free radical formed by the addition of one electron to O2.Ref: Ganongs Review of Medical Physiology Twenty-Third Edition Page no: 64 