The fact that these peroxide and superoxide anions react with components of our cells such as DNA and proteins and that can actually cause detrimental effects. Now, there are many different ways by which the cells of our body can actually destroy or convert these peroxide and superoxide molecules into safer molecules. Now, the first thing that I should mention is complex four, which actually produces a peroxide bridge as an intermediate molecule doesn't simply let go of these molecules. So these complexes, these enzymes which basically reduce things like oxygen molecules, actually hold on to these molecules very tightly and they only let go under certain conditions. So we see that complex four holds the oxygen and its derivatives very tightly. It only releases it upon the conversion of these molecules into safer molecules as in this case, into water.