Hydrogen Oxygen Species ( Ros ) - 1029 Words

BACKGROUND Oxygen is abundant in the atmosphere and it is essential for various biochemical processes such as energy production and â€Å"biological processes such as metabolic regulation, metabolic energy control, and activation or inactivation of biomolecules, signal transduction, cell exchange, endothelium related vascular functions and gene expression† in most living organisms. Oxidation is the major reaction involved during these processes and it often results in the formation of free radicals as oxygen can oxides other molecules. These free radicals are highly unstable and reactive due to the presence of unpaired orbitals (Magder, 2006). . 2.1. Reactive Oxygen Species (ROS) â€Å"Reactive oxygen species (ROS) are radicals or chemical species that partake in reactions that involve gaining or loss of electron (radical reactions) but are not true radicals in that they do not have unpaired electrons†. ROS include non-radical ROS such as hydrogen peroxide (H2O2), and hypochlorous acid (HOCl), ozone (O3) and singlet oxygen (1O2) while radical ROS consist of super oxide anion radicals (O2ââ€" -) and hydroxyl radical species (ââ€" OH). Besides oxygen-based radicals, reactive nitrogen species(RNS) such as nitric oxide (NO) and nitrogen dioxide (NO2) and peroxynitrile also exist (Magder, 2006). 2.1.1. Formation of ROS Free radicals formation involves the breakage of a chemical bond in molecules such that each fragment keeps one electron, by cleavage of a radical to give another radical and, alsoShow MoreRelatedPlant Products Essay1518 Words   |  7 Pagesstill having an important role as potential source of therapeutics in health systems across the world.The recent growth in the knowledge of free radicals and reactive oxygen species (ROS) is producing a medical revolution promising a new age of health and disease management. A free radical can be defined as any molecular species capable of independent existence that contains an unpaired electron in an atomic orbital. The presence of an unpaired electron leads to certain similar properties thatRead MoreAntioxidants And Its Effects On Health1460 Words   |  6 Pagesand more just stick around, I promise your time will be well spent. In short, antioxidants do exactly what their name implies, i.e., they protect against oxidative stress and damaged caused by reactive oxygen species (ROS) otherwise known as free radicals, but a foundational knowledge of these ROS is essential to understand the role of antioxidants in body dynamics. To begin we need to understand what free radicals are and where they come from. Concisely free radicals are highly reactive moleculesRead MoreHypoxia Case Study724 Words   |  3 Pagesfactor (HIF). HIF-1ï  ¢ heterodimerizes with one of two HIF-ÃŽ ± isoforms (HIF-1ÃŽ ± and HIF-2ÃŽ ±) and drives the expression of pro-inflammatory cytokines that mediate macrophage aggregation, invasion, and motility. The stability of HIF-ÃŽ ± subunits is regulated by oxygen availability. Under normoxia conditions, prolylhydroxylases hydroxylates HIF-ÃŽ ± and marks it for proteasomal degradation in a process mediated by von Hippel-Lindau tumor suppressor protein (VHL)-dependent ubiquitination. Under hypox ic conditions, PHDsRead MorePhysiological And Pathological Systems Within The Circulatory System859 Words   |  4 Pagesphysiological and pathological systems within the circulatory system. Redox signalling is usually induced by an overproduction of reactive oxygen species (ROS) which can alter the functions of cell processes. Harris,(2012). ROS are radicals that contain one or more unpaired electrons and can be the oxygen radical superoxide or the non-radical hydrogen peroxide (H2O2). ROS can also contribute to vascular modelling by phenotype modification of the smooth muscle cells, growth and even the death of cells.Read MorePlants respond to environmental stresses such as drought, excessive salinity and low temperature1400 Words   |  6 Pagesand Boyer, 1985; Sharp et al., 1988). The degree of growth inhibition due to osmotic stress depends on the duration and the intensity of drought stress and on the genotype of plant species (Bartels and Sunkar, 2005). The efficiency of water uptake is an important determinant of drought resistance within plant species. It was reported that the water uptake depends on roots size (length or mass), activity and distribution (Huang and Gao, 2000). The development of the roots system as an adaptive responseRead MoreAntioxidant and Anti-Inflammatory Properties of Lunasin618 Words   |  3 Pagesdevelopment of approximately 15–20% of malignancies worldwide52, being clearly associated with increased risk of cancer and cancer progression53. It is believed that persistent inflammatory cells recruitment, repeated generation of reactive oxygen species (ROS), pro-inflammatory mediators and continued proliferation of genomically unstable cells contribute to neoplasic transformation which ultimately result in tumor invasion and metastasis54. Determination of anti-inflammatory and/or antioxidativeRead MoreOxidative Stress Case Study1617 Words   |  7 Pageslipid peroxidation and that was compatible with the study of Rao et al. [22] who suggested that the decrease in MDA concentration could be due to the ability of HMB to scavenge secondary reactive radicals or to prevent the formation of superoxide or hydrogen peroxide in response to IR exposure. It was stated that HMB is a potent ONOO_ scavenger that can protect the cells against peroxy nitrite-induced diseases [41]. Along these lines, the reaction between O2 ·- and NO may be diminished by the activityRead MoreEnvironmental Effects Of Reactive Oxygen Cells1537 Words   |  7 PagesPrimitive earth’s atmosphere was filled with molecular oxygen (O2) by the invasion of cyanobacteria (Schopf, 1993). Atmospheric oxygen has played a major role in the evolution and is responsible for catabolic activities of living organisms. On one hand, reactive oxygen species (ROS), as we know it can prove lethal to the living organisms. But on the other hand, ROS can also play a major role as a second messenger in the cell and control many essential processe s from cell death, cell differentiationRead MoreOxidative Stress Response1611 Words   |  7 Pagesphagolysosomes and gets fumigated and killed. During infection, Candida species are exposed to higher levels of reactive oxygen species (ROS), reactive nitrogen species (RNS) and antimicrobial peptides, low pH and reactive chloride species (HOCl) inside macrophages and neutrophils, and survival through these harsh conditions is essential for establishing disease and virulence. C. albicans evolved systems to directly scavenge the ROS produced by host cells and establish systemic infection. C. albicansRead MoreCryptococcus Neoformans is a Basidiomycetous Yeast Fungus1992 Words   |  8 Pagesmacrophages, and neutrophils produce reactive oxygen species (ROS) which kill intruding pathogens by oxidative or respiratory burst. Phagocytic cells increase oxygen production and convert dimolecular oxygen into superoxide anions and hydrogen peroxide by the NADPH oxidase complex (Graham et al. 2 007). The ROS produced are toxic to many pathogens like fungi and bacteria and can cause damage to the pathogen’s nucleic acid, and proteins. Reactive oxygen species produced by the host cells are associated