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Ros Essay

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How is physiological proton leak from the mitochondrial inner membrane via uncoupling advantageous?
According to the article, physiological proton leak from the mitochondrial inner membrane via uncoupling is advantageous because it triggers a decrease in ROS production. The decrease occurs because a the described process (in the question) triggers a slight increase in ROS production which then induce a proton leaks that decrease ROS production.
How is ROS generated in mitochondria?
ROS refers to reactive oxygen species, which by definition is not limited to one singular species but rather any molecule that contains oxygen and is also highly reactive - most contain unpaired electrons. They can be generated spontaneously, but the mitochondria are the largest producer of ROS in most cells. Within the mitochondria ROS production occurs in the respiratory chain in Complex I and III. The actual location on Complex I where ROS generation occurs isn’t 100% known, however it is known that superoxide is generated on the matrix side of the mitochondrial inner membrane (MIM). According to the article, ROS generation most likely occurs through the FMN prosthetic group and an inhibitor, rotenone. Rotenone acts as a complex I-ubiquinone binding site inhibitor and when substrates that are NADH-linked are present superoxide production increases (ROS production increases). An alternate theory for the site on Complex I is the Q-binding site. Here semiquinone will form sometimes when Q …show more content…

They are uncoupling proteins that work together to control mitochondrial ROS formation. They work to move protons from the MIM space into the matrix by using the electrochemical gradient present. For UCP2 and UCP3 the process of reversible glutathionylation of the 2 proteins regulates the activation (UCP2) and deactivation (UCP3) of the leak.
Describe the role of antioxidative defense systems in controlling ROS

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