sentences:  The former involves the activation of membrane enzyme systems that lead to a stimulation of oxygen uptake (known as the respiratory burst), and its reduction to reactive oxygen intermediates (ROIs), molecular species that are highly toxic for microorganisms.The enzyme responsible for the elicitation of the respiratory burst is known as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which is composed of five subunits.One component is a membrane cytochrome made up of two protein subunits, gp91phox and p22phox; the remaining three components are cytosolic-derived proteins