Reactive oxygen species (ROS) are unstable, or reactive, compounds that result from the partial reduction of oxygen. ROS can cau
se damage to molecules, including membrane lipids and nucleic acids, and may be associated with some diseases. Which of these compounds are reactive oxygen species
Reactive oxygen species (ROS) can be defined as highly reactive chemical compounds formed from molecular oxygen (O2). ROS are generated as a normal product of cellular metabolism, and also as a response to different environmental/internal cellular stimuli (e.g., cytokines, xenobiotics, pathogenic invasion). For example, hydroxyl radicals (·OH) are a type of ROS generated in the mitochondria which are capable of inducing oxidative stress in different cells and also trigger chronic inflammation. Moreover, hydrogen peroxide (H2O2) molecules represent another type of ROS which are produced during the stereoselective deamination of amino acids, i.e., the building blocks of proteins. These molecules (H2O2) exhibit toxic effects on the cell (e.g., DNA damage). Finally, singlet oxygen (1O2) is an excited state of molecular oxygen (O2) that is generated during photosynthesis in the photosystem II (PSII) of chloroplasts.
During interphase, the cell grows and the DNA replicates. After that there's the mitotic phase where the replicated DNA and the contents in the cytoplasm are sperated in a way that the cell divides.
