Reactive Oxygen Species (ROS) are oxygen containing molecules which include oxygen ions as well as peroxides. ROS are produced as a natural byproduct following normal cellular metabolism of oxygen and play a vital role in the cellular signaling mechanisms and maintenance of the cellular environment (homeostasis).
How reactive oxygen species produced?
According to scientists, ROS are made within aerobic organisms which derive their energy from reduction of oxygen. This usually takes place within mitochondria through electron transfer. During this process, there are byproducts such as super oxide, peroxide, hydroxide being made and it is considered normal during such processes. At the same time, similar unstable compounds will also be created through peroxidation of lipids. Apart from the mitochondria, such oxidation processes can also take place in other parts of the cell which includes the cytoplasmic reticulum as well as the cell membrane. Together, all these elements are known as ROS. Apart from the molecules mentioned above, biological systems do contain many other ROSs and these include hypochlorous acid (HOCL), ozone and singlet oxygen.
What is the use of ROS in cell biology?
In the beginning, researchers believed that these byproducts were nothing more than ‘oxidative stressors’ to the cell which can cause damage and disease in living organisms. However, recent studies have shed light on its potential use as a signaling molecule in respect to maintaining physiology as well as promote fitness in certain instances. Thus, ROS have been linked with oxidative signaling that takes place in instances such as platelet recruitment in the event of clot formation at times of bleeding, induction of host defense genes, mobilization of ion transport systems, and providing links to adaptive immune responses through recruitment of leukocytes.
What are the potential damages that can be caused by ROS?
In general, reactive oxygen species are known to cause damage to the DNA, oxidize polyunsaturated fatty acids, oxidize amino acids in proteins as well as inactivate certain specific enzymes thus halting certain biological processes. Altogether, the ROS has the potential to initiate programmed cell death and thus ischemic events such as stroke and cardiovascular accidents, promote inflammatory diseases, cause hearing impairment through cochlear damage, contribute to congenital deafness as well as towards ototoxicity due to certain drugs.
How does ROS being handled inside cells?
In a normal status, the cellular mechanisms will be able to balance the ROS production with an equally efficient ROS scavenging processes. These processes are fueled by enzymes such as peroxiredoxins. At the same time, antioxidants such as ascorbic acid, tocopherol and uric acids will also play a major role in the antioxidation taking place within the living cell.