Dictionary > Reactive oxygen species

Reactive oxygen species

Chemically reactive molecules and ions of oxygen with an unpaired electron
Reactive oxygen species are molecules and ions containing reactive oxygen. By reactive, it means that the oxygen has an unpaired electron. In biological systems, the presence of reactive oxygen species affects metabolic activities of the cell. They have an effect in homoeostasis and cell signaling, and associated with certain manifestation of diseases. An increase of reactive oxygen species, for instance, could be damaging to the cell structures and biomolecules (e.g. proteins, lipids, and DNA). Some of the factors that increase their level are heat, metal toxicity, nutrient deficiency, UV radiation, ionizing radiation, etc. In cell signaling, they may act as cellular messengers and cause disruptions in the system. They are produced as a stress response of the cell to these factors. An excessive amounts of reactive oxygen species could lead to oxidative stress, which is defined as a disturbance caused by the accumulation of reactive oxygen species A highly oxidized environment inside the cell manifests when the biological system is unable to detoxify reactive intermediates. In humans, it is presumed to be involved in the development of cancers, Alzheimer’s disease, vitiligo, autism, atherosclerosis, etc. Reactive oxygen species, though, are essential as they are involved in the immune response against pathogens.
Examples of reactive oxygen species are peroxides, singlet oxygen, superoxide, and hydroxyl radical.

  • ROS

See also:

  • oxygen
  • oxidative stress
  • Mentioned in:

    You will also like...

    3D rendering of an antibody
    Passive and Active Types of Immunity

    Lymphocytes are a type of white blood cell capable of producing a specific immune response to unique antigens. In thi..

    Physical growth
    Physical Development in Humans

    This tutorial elaborates on the physical development of humans, particularly from puberty to adulthood. Read this tutori..

    Animal Water Regulation

    Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

    Pikas are an indicator species for climate change
    Indicator Species and Endangered Species

    Certain species are capable of expressing characteristics indicative of the state of the ecosystem they occupy. They are..

    Lotic community of algal species
    Lotic Communities & Algae

    Lotic communities have conditions that are rather harsh for typical plants. Thus, the diversity of plant species in loti..

    Population Regulation in an Ecosystem
    Population Regulation in an Ecosystem

    With regard to the population size of a species and what factors may affect them, two factors have been defined. They ar..