So these two molecules can be used in a variety of different ways. For instance, the oxygen can be used by the electron transport chain to generate ATP molecules and water molecules can be used in a variety of different types of processes. For instance, hydrolysis processes. Now, one last thing I'd like to mention is the fact that exercise so if we continually exercise on a daily basis that can actually be very beneficial. And one benefit of exercising is that exercising actually increases the concentrations, the levels of these enzymes, protective enzymes inside our cells. So as we exercise we increase the levels of superoxide this mutates and Catalyte and catalyst because exercising actually increases the likelihood that we're going to produce these reactive oxygen species.