The new cobalt catalyst also splits water into hydrogen and oxygen without creating the kind of reactive oxygen molecules that can damage DNA or other processes essential to continuing life. (scientificamerican.com)
Otherwise, it would be difficult to tell what the «normal» amount of circulating reactive oxygen molecules in the animal's body was. (sciencedaily.com)
The immune system may kick in when animals eat, releasing reactive oxygen molecules to kill microbes on food, helping to protect from disease. (sciencedaily.com)