The Effect Of Peroxynitrite And Nitrating Agents On Mitochondrial Respiratory Complexes

In this experiment, the naturally occurring peroxidase is extracted from homogenized turnip (Brassica rapa) pulp (Coleman 2016). Its role in the environment is to remove toxic hydrogen peroxide during metabolic processes where oxygen is used (Coleman 2016). The goal of this experiment is to evaluate the change of absorbency of turnip peroxidase within a metabolic reaction utilizing oxygen. Any change noted is indicative of the peroxidase removing hydrogen peroxide. Within this experiment, the extract will be prepared, the amount of enzyme will be standardized, and the effect of changing the optimal conditions will be observed. If the enzyme concentration is increased then the rate of the reaction decrease. If the pH of solutions used is increased

H2O2 is commonly known as hydrogen peroxide and it is a strong oxidizer and a naturally produced compound in humans as a by-product of oxidative metabolism. Because of this, humans also produce the enzyme catalase peroxidases in order to convert small amounts of H2O2 into oxygen and water. It uses the following chemical formula:

This investigation will be carried out to investigate the rate of reaction of the enzyme catalase on the substrate hydrogen peroxide.

“Peroxisomes are so named because they usually contain enzymes that use oxygen to remove hydrogen atoms from specific substrates in an oxidative reaction that produces hydrogen peroxide (H2O2) (McCance & Huether, pg. 7).

The purpose of this experiment was to simply measure oxygen production rates released from decomposed hydrogen peroxide under different conditions (concentration of enzymes, temperature, and PH level).

Peroxidase is a turnip enzyme; it is used in the oxidation of hydrogen peroxide to lower activation energy, speeding up the reaction. The activity of peroxidase is highly dependent on its environment and most importantly the pH level. Peroxidase has been the focus of many recent studies and is believed to possibly reduce swelling among other things. We conducted an experiment testing the effect different levels of pH had on the reaction rate of peroxidase. In the experiment we created different solutions all containing hydrogen peroxide, peroxidase, and guaiacol. However each cuvette contained a different pH level, 2,5,7,or

The effectiveness of peroxidase was measured in a varying pH environment. The environment’s pH can range from   1-14, 7 being neutral, 7-1 being more and more acidic towards 1, and 8-14 being more and more basic towards 14 (Raven, 2011).

With all living organisms, a process known as cell respiration is integral in order to provide the body with an essential form of energy, adenosine triphosphate (ATP). Oxygen, although an essential part of this process, can form reactants from colliding with electrons associated with carrier molecules. (pb101.rcsb.org, 2017). Hydrogen peroxide is an integral product of this reaction but is known to impose negative effects on the body if high levels are introduced. Explicitly, this reaction is caused “If oxygen runs into (one of these) carrier molecules, the electron may be accidentally transferred to it. This converts oxygen into dangerous compounds such as superoxide radicals and hydrogen peroxide, which can attack the delicate sulphur atoms and metal ions in proteins.” (pdbh101.rcb.org, 2017). Research has suggested that the hydrogen peroxide can be converted into hydroxyl radicals, known to mutate DNA, which can potentially cause bodily harm due to DNA’s role in the synthesis of proteins. These radicals can cause detrimental effects on the human body, and studies have suggested a link to ageing. Due to the harmful effects of these H2o2, it is important that the body finds a way to dispose of hydrogen peroxide before concentrations are too great.

The purpose of this experiment is to learn the effects of a certain enzyme (Peroxidase) concentration, to figure out the temperature and pH effects on Peroxidase activity and the effect of an inhibitor. The procedure includes using pH5, H202, Enzyme Extract, and Guaiacol and calibrating a spectrophotometer to determine the effect of enzyme concentration. As the experiment continues, the same reagents are used with the spectrophotometer to determine the temperature and pH effects on Peroxidase activity. Lastly, to determine the effect of an inhibitor on Peroxidase, an inhibitor is added to the extract. It was found that an increase in enzyme concentration also caused an increase in the reaction rate. The reaction rate of peroxidase increases at 40oC. Peroxidase performed the best under pH5 and declined as it became more basic. The inhibitor (Hydroxy-lamine) caused a decline in the reaction rate. The significance of this experiment is to find the optimal living conditions for Peroxidase. This enzyme is vital because it gets rid of hydrogen peroxide, which is toxic to living environments.

The purpose of this report is to find out the effect of change in the Temperature, PH, boiling, concentration in peroxidase activity. Peroxidase is an enzyme that converts toxic hydrogen peroxide (H2O2) into water and another harmless compound. In this experiment we use, turnips and horseradish roots which are rich in the peroxidase to study the activity of this enzyme. The activity of peroxidase with change in temperature was highest at 320 Celsius and lowest at 40C. The activity of peroxidase was highest at a pH of 7, while it was lowest at pH of 9.Peroxidase activity was very low and constant with boiled extract, while the activity was moderate

Observing how the enzyme catalase found in chicken and beef livers breaks down hydrogen peroxide at varying pH levels and temperatures.

The function of peroxisomes is very crucial to maintain homeostasis in the cell. Peroxisomes contain enzymes that oxidize certain molecules normally found in the cell, notably fatty acids and amino acids. Those oxidation reactions produce hydrogen peroxide, which is the basis of the name peroxisome. However, hydrogen peroxide is potentially toxic to the cell, because it has the ability to react with many other molecules. Therefore, peroxisomes also contain enzymes such as catalase that convert hydrogen peroxide to water and oxygen, thereby neutralizing the toxicity. In that way peroxisomes provide a safe location for the oxidative metabolism of certain molecules. Peroxisomes produce chemicals as well as break them

During oxidation of oxymyoglobin, both superoxide anion and hydrogen peroxide are produced and further react with iron to produce hydroxyl radical. The hydroxyl radical has the ability to penetrate into the hydrophobic lipid region and hence facilitates lipid oxidation. The prooxidant effect of oxymyoglobin on lipid oxidation is concentration dependent. At equimolar concentrations, oxymyoglobin shows higher prooxidative activity towards lipid than metmyoglobin. However, the catalytic activity of metmyoglobin is promoted by hydrogen peroxide. The reaction between hydrogen peroxide and metmyoglobin results in the formation of two active hypervalent myoglobin species perferrylmyoglobin and ferrylmyoglobin. Those two hypervalent myoglobin species

Previously mitochondria were considered to be static and isolated organelles. However, it has now been established that mitochondria form a complex, interconnected, and highly dynamic network. Mitochondria dynamics also involves changes in mitochondrial morphology, number in the cell and movement along the cytoskeleton. Mitochondrial dynamics is said to be tightly regulated by mitochondrial fusion and fission.

Heme-group containing mammalian peroxidase enzymes possess a highly conserved structure and partake in reactions associated with the development of inflammatory diseases, defense system of the host as well as the biogenesis of hormones (Péterfi et al., 2009)(Cheng, Salerno, Cao, Pagano, & Lambeth, 2008). The heme-binding sites of peroxidase enzymes possess specific features that are preserved as well as characteristics including disulphide bonds forming between cysteine residues, a binding site for calcium as well as specific amino acid residues which interact with the side chains present on the heme propionate (Chengreference). In the presence of hydrogen peroxide (H2O2), these enzymes catalyse the oxidation of a range of substrates (Péterfi et al., 2009). In order to stabilise the extracellular matrix (ECM) of lower animal species as well as plants, peroxidases enzymatically catalyse the cross linkage of these extracellular proteins through the formation of dityrosine bridges using H2O2 (Péterfi et al., 2009). The family of mammalian peroxidases consists of myeloperoxidase, eosinophil peroxidase and lactoperoxidase (which are involved in the defense system of the host) as well as thyroid peroxidase (involved in the biogenesis of thyroid hormones) and the mammalian peroxidasin (PXDN) (Péterfi et al., 2009).