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The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. [ 1 ] A free radical is any atom or molecule that has a single unpaired electron in an outer shell. [ 2 ] While a few free radicals such as melanin are not chemically reactive, most biologically relevant free radicals are highly ...
Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. [1] Disturbances in the normal redox state of cells can cause toxic effects through the production of peroxides and free radicals ...
What kinds of damage can free radicals cause? Excess free radicals, and in turn oxidative stress, can impact how the body ages and produce visible evidence such as wrinkles and sunspots ...
In chemistry and biology, reactive oxygen species (ROS) are highly reactive chemicals formed from diatomic oxygen (O2), 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 ...
Lipid peroxidation, or lipid oxidation, is a complex chemical process that leads to oxidative degradation of lipids, [1] resulting in the formation of peroxide and hydroperoxide derivatives. [2] It occurs when free radicals, specifically reactive oxygen species (ROS), interact with lipids within cell membranes, typically polyunsaturated fatty ...
Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue (re- + perfusion) after a period of ischemia or lack of oxygen (anoxia or hypoxia). The absence of oxygen and nutrients from blood during the ischemic period creates a condition in which ...
Scientific career. Institutions. Shell Oil, Emeryville, California; University of Nebraska. Denham Harman (February 14, 1916 – November 25, 2014) was an American medical academic who latterly served as professor emeritus at the University of Nebraska Medical Center. [1][2][3] Harman is known as the " father of the free radical theory of aging ...
Vitamin C: Mitchell recommends this antioxidant for its many functions, which includes “stimulating collagen production, brightening the skin, and fighting free radical damage caused by sun ...