Search results
Results from the WOW.Com Content Network
In chemistry and biology, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (O 2), water, and hydrogen peroxide. Some prominent ROS are hydroperoxide (O 2 H), superoxide (O 2-), [1] hydroxyl radical (OH.), and singlet oxygen. [2] ROS are pervasive because they are readily produced from O 2, which is ...
Reactive nitrogen species act together with reactive oxygen species (ROS) to damage cells, causing nitrosative stress. Therefore, these two species are often collectively referred to as ROS/RNS. Reactive nitrogen species are also continuously produced in plants as by-products of aerobic metabolism or in response to stress. [3]
Respiratory burst (or oxidative burst) is the rapid release of the reactive oxygen species (ROS), superoxide anion (O − 2) and hydrogen peroxide (H 2 O 2), from different cell types. This is usually utilised for mammalian immunological defence, but also plays a role in cell signalling.
When a phagocyte ingests bacteria (or any material), its oxygen consumption increases. The increase in oxygen consumption, called a respiratory burst, produces reactive oxygen-containing molecules that are anti-microbial. [32] The oxygen compounds are toxic to both the invader and the cell itself, so they are kept in compartments inside the cell.
Reactive nitrogen ("Nr"), also known as fixed nitrogen [1], refers to all forms of nitrogen present in the environment except for molecular nitrogen (N 2 ). [ 2 ] While nitrogen is an essential element for life on Earth, molecular nitrogen is comparatively unreactive, and must be converted to other chemical forms via nitrogen fixation before it ...
The six aforementioned elements are used by organisms in a variety of ways. Hydrogen and oxygen are found in water and organic molecules, both of which are essential to life. Carbon is found in all organic molecules, whereas nitrogen is an important component of nucleic acids and proteins.
Strictly speaking, the free radical theory is only concerned with free radicals such as superoxide ( O 2 −), but it has since been expanded to encompass oxidative damage from other reactive oxygen species (ROS) such as hydrogen peroxide (H 2 O 2), or peroxynitrite (OONO −). [4]
Biological functions of nitric oxide are roles that nitric oxide plays within biology. Nitric oxide (nitrogen monoxide) is a molecule and chemical compound with chemical formula of N O. In mammals including humans, nitric oxide is a signaling molecule involved in several physiological and pathological processes. [1]