Oxymyoglobin

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

This experiment looked at how substrate concentration can affect enzyme activity. In this case the substrate was hydrogen peroxide and the enzyme was catalase. Pieces of meat providing the catalase were added to increasing concentrations of hydrogen peroxide in order to measure the effect of hydrogen peroxide concentrations on the enzyme’s activity. The variable measured was oxygen produced, as water would be too difficult to measure with basic equipment.

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

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).

“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).

We hypothesized that a medium pH buffer added to the hydrogen peroxide an peroxidase reaction would be the best condition for the enzyme activity due to it being the more neutral than the high, being basic, and low, being acidic, pH.

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.

Peroxidase is an enzyme that breaks down hydrogen peroxide in our cells (Bansal et. al., 2016). Peroxidase is essential in life because hydrogen peroxide can cause damage to the cell. Hydrogen peroxide is the substrate to the peroxidase enzyme, where it binds to the active site and is broken down into water. In order to monitor the breakdown of hydrogen peroxide, the colorless dye guaiacol binds to the peroxidase and becomes oxidized as hydrogen peroxide is reduced to water, which then turns brown. Hydroxylamine is an inhibitor that has a similar structure to hydrogen peroxide. When hydroxylamine binds to the active site of peroxidase, it inhibits hydrogen peroxide from binding, thus preventing the breakdown of hydrogen peroxide (Lab Handout,

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.

Catalase is an enzyme needed to break down hazardous hydrogen peroxide into nonhazardous oxygen and water. This is needed for organisms as the reaction rate of the decomposition of hydrogen peroxide is too slow to protect cells against the oxidation of hydrogen peroxide. The purpose of this experiment is to test the concentration of hydrogen peroxide on catalase and variation in temperature of catalase to find the optimal values that will produce the highest rate of products. It was hypothesized that as the concentration of substrates increases, the reaction rate will as well. The null hypothesis for this is that the substrate concentration will have no effect on the reaction rate. For the varying temperature of catalase, it was hypothesized that as the temperature increases, the reaction rate will increase as well until the enzyme is denatured. The null hypothesis for this is that varying temperature will have no effect on the reaction rate. The experiment was completed by using a 10mL graduated cylinder filled with water that collected oxygen gas that was produced by the reaction. From this experiment, one can see that as the amount of hydrogen peroxide concentration increases, the rate of the reaction increases as well. The results support this as the average reaction rate starts at 0.00 mL O2/min for 0.0% hydrogen peroxide and raises to 38.17 mL O2/min for 0.8% hydrogen peroxide. As the temperature of catalase was increased, rate of reaction continued to

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

IsoKs react covalently to lysyl residues of proteins to form a stable adduct and intramolecular cross-links (Iyer, Ghosh et al. 1989, Boutaud, Brame et al. 1999, Brame, Salomon et al. 1999). These molecules react at a rate that far exceeds other well studied products of lipid peroxidation, including 4-hydroxynonenal (4-HNE) (Brame, Salomon et al. 1999) (Fig. 1.3A). Results from in vitro oxidation of arachidonic acid strongly suggests that IsoKs form in vivo; however when tissues such as plasma and urine, IsoKs were not detected, although significant quantities of F2-IsoPs were detected by GC/MS. Analysis of iron/ADP/ascorbate treated liver microsomes also failed to detect any IsoKs, despite containing abundant F2-IsoPs. The reason for the failure to detect IsoKs in biological samples became apparent when studies were carried out to quantify the reactivity of IsoKs with proteins.

DL-2-hydroxy-4(methylthio)butanoic acid (DL-HMTBA) exhibits a higher antioxidant capability in vitro as compared to DL-methionine, but the mechanism is not known. A total of 400 8-d-old broilers were allotted to a 2 [Low (14-16℃) or control temperature] × 2 (0.17% or 0.51% DL-HMTBA) factorial arrangement to investigate effects of DL-HMTBA on the gene expression related to oxidative stress in low temperature. The hepatic glutathione (GSH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were decreased, while protein carbonyl and malodndialdehyde content in lung were increased in low temperature (P10-fold decrease in CβS protein levels. Therefore, it indicated that DL-HMTBA supplementation may increase MAT-1A and CβS gene expression, to enhance Met trans-sulfuration to GSH, then to increase antioxidant capacity of broilers exposed to low ambient temperature (39). Further work is needed to determine whether the